Thank you for the question. I am sorry to hear about his matter. It really comes down to the fact they are claiming the events of their complaint constitutes a breach of contract and therefore have chosen to terminate the contract, thus they don't need to pay for the remainder. However if you dispute there has been a breach of contract, you can look at raising a small claims acton to recover your money. If that is the case, you would both present your evidence to a judge who can decide if there is breach or not.
Prior to intimating small claim proceedings, you will require to send a letter to the respondent. It is a simple letter stating that if they do remedy the matter as you have outlined (in the same letter), you will take legal action against them. This is referred to as a. pre-action protocol letter. You can complete the forms for a claims action easily online. You will have to highlight what the issues are and tell them how much you are claiming for, to be honest the first are straight forward and self-explanatory. If you feel you can do this yourself then you don’t really need to hire a solicitor, but I will provide details for you in case you feel you want to. You will then receive a response to the claim and a court date. On the day (unless they offer a settlement) you will appear at the local court and basically provide your evidence and give you claim to the judge, and they will response. The judge will assess the merits of the claim and defence and make a judgement this should be relatively easy for you to prove so the respondent may well offer a settlement in the meantime.
I shall provide you with a helpful link that will assist you in finding a solicitor/representative near your local area. This will provide you with someone nearby your area who can assist you if required.
I hope this information proved helpful. You will find a local solicitor who deals with these matters on the law society webpage which is as follows;
https://solicitors.lawsociety.org.uk/ (England)
https://www.lawscot.org.uk/find-a-solicitor/ (Scotland)
https://www.lawsociety.ie/Find-a-Solicitor/Solicitor-Firm-Search/ (Ireland)
https://www.lawsoc-ni.org/solicitors (N. Ireland)
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