I hired a company to install concrete fencing and a gate in my back garden. The quality of the work is poor, some wooden panels are loose and the gate doesn’t shut properly. I paid before I inspected the work. What can I do?

When you put your trust in a trader and they don’t meet your expectations it can be really frustrating.

When there’s a problem caused by a trader, you should be able to get it fixed or get some money back. Evidence is important – take photos and make notes about what happened and when, including times and dates, and keep hold of receipts or other proof of payment.

People can experience different types of problems with traders, and there’s specific advice available on our website depending on what the issue is. In your situation, it’s important to note if a trader hasn’t done a good job with ‘reasonable care and skill’, the Consumer Rights Act 2015 entitles you to ask for the problem to be fixed or for a refund.

This is something you can mention when you take the problem up with the trader and cite your evidence. They should fix the problem within a reasonable amount of time, without causing you too much inconvenience. The law doesn’t say what counts as reasonable, so you’ll have to agree on it with them.

If they can’t or won’t fix the problem, you can ask for a partial or full refund, depending on how bad the problem is. You’ll have to come to an agreement about how much you should get. It’s a good idea to start by suggesting a figure and explaining why you think it’s reasonable, then take it from there. Once you’ve agreed on the amount with the trader the law says you should get your refund within 14 days.

If you can’t come to an agreement, or they refuse to fix the problem or give you a refund, there are other steps you can take – including complaining to your card provider if you paid by card.

You can check if the trader is a member of a trade association or quality scheme. If they are, they might have to follow certain rules, and if they’ve broken them you could get help to take your complaint further. They might be part of an alternative dispute resolution (ADR) scheme – a way of solving disagreements with a trader without going to court – or they might agree to use one.

If the trader isn’t part of an ADR scheme, and you’ve already complained to your card provider and the complaint isn’t resolved, you may be able to complain to the Financial Ombudsman Service.

Anyone who is experiencing a problem with building work, decorating or home improvements can contact the Citizens Advice Consumer Service for advice and support from a trained adviser. The helpline number is 0808 223 1133.

Fe wnes i logi cwmni i osod ffens â physt concrit a giât yn fy ngardd gefn. Mae ansawdd y gwaith yn wael, mae rhai paneli pren yn rhydd ac nid yw’r giât yn cau’n iawn. Fe dalais i cyn archwilio’r gwaith. Beth alla i ei wneud?

Pan fyddwch chi’n ymddiried mewn masnachwr ac nad ydyn nhw’n bodloni eich disgwyliadau, gall fod yn hynod rwystredig.

Os yw masnachwr yn achosi problem, yna fe ddylai ei datrys neu roi rhywfaint o’ch arian yn ôl. Mae tystiolaeth yn bwysig – cymerwch luniau a gwnewch nodiadau am yr hyn a ddigwyddodd a phryd, gan gynnwys amseroedd a dyddiadau, a chadwch dderbynebau neu brawf arall o daliad.

Gall pobl brofi gwahanol fathau o broblemau gyda masnachwyr, ac mae cyngor penodol ar gael ar ein gwefan yn dibynnu ar beth yw’r broblem. Yn eich sefyllfa chi, mae’n bwysig nodi, os nad yw masnachwr wedi gwneud gwaith da gyda ‘gofal a sgil rhesymol’, mae Deddf Hawliau Defnyddwyr 2015 yn rhoi’r hawl i chi ofyn am gael datrys y broblem neu am ad-daliad.

Dyma rywbeth y gallwch ei grybwyll pan fyddwch chi’n trafod y broblem gyda’r masnachwr ac yn dyfynnu eich tystiolaeth. Dylent ddatrys y broblem o fewn cyfnod rhesymol o amser, heb achosi gormod o anghyfleustra i chi. Nid yw’r gyfraith yn dweud beth sy’n cyfrif fel rhesymol, felly bydd yn rhaid i chi gytuno ar hyn gyda nhw.

Os na allant neu nad ydynt am ddatrys y broblem, gallwch ofyn am ad-daliad rhannol neu lawn, yn dibynnu ar ba mor ddrwg yw’r broblem. Bydd yn rhaid i chi ddod i gytundeb ynghylch faint y dylech chi ei gael. Mae’n syniad da dechrau drwy awgrymu ffigur ac egluro pam rydych chi’n meddwl ei fod yn rhesymol, yna symud ymlaen o’r fan honno. Unwaith i chi gytuno ar y swm gyda’r masnachwr, mae’r gyfraith yn dweud y dylech chi gael eich ad-daliad o fewn 14 diwrnod.

Os na allwch ddod i gytundeb, neu os ydyn nhw’n gwrthod datrys y broblem neu roi ad-daliad i chi, mae camau eraill y gallwch eu cymryd – gan gynnwys cwyno i ddarparwr eich cerdyn os gwnaethoch dalu â cherdyn.

Gallwch wirio a yw’r masnachwr yn aelod o gymdeithas fasnach neu gynllun ansawdd. Os ydyn nhw, efallai y bydd yn rhaid iddyn nhw ddilyn rheolau penodol, ac os ydyn nhw wedi’u torri gallech chi gael help i fynd â’ch cwyn ymhellach. Efallai eu bod nhw’n rhan o’r cynllun datrys anghydfodau amgen (AD), sef ffordd o ddatrys anghytundebau gyda masnachwr heb fynd i’r llys – neu efallai y byddan nhw’n cytuno i ddefnyddio un.

Os nad yw’r masnachwr yn rhan o gynllun AD, ac rydych eisoes wedi cwyno i ddarparwr eich cerdyn ac nad yw’r gŵyn wedi’i datrys, efallai y gallwch chi gwyno i’r Gwasanaeth Ombwdsmon Ariannol.

Gall unrhyw un sy’n cael problem gyda gwaith adeiladu, addurno neu welliannau i’r cartref gysylltu â Gwasanaeth Defnyddwyr Cyngor ar Bopeth am gyngor a chefnogaeth gan gynghorydd hyfforddedig. Rhif y llinell gymorth yw 0808 223 1133.