Thanks very much for your question. My name's XXXXX XXXXX I'm going to assist you with it.
If multiple attempts at communication have been made over a significant period time, there are three options. The first is to contact Trading Standards, the second is to check whether the garage is a member of any trade association that offers a dispute resolution service and the third is to issue a claim. Once a letter before claim has been sent (advising that legal proceedings will be commenced if the matter is not resolved within a specific time) a claim can be started once the period has expired.
When claiming for third party repairs costs it is important to ensure that sufficient opportunity was given for the defendant to carry out the repairs themselves. It is therefore important to have copies of all correspondence relating to this, along with the report relating to the cause of the damage.
To issue a claim you can use the online service at www.moneyclaim.gov.uk and money claim less than £10,000 are generally allocated to the small claims track. Claimants in the smalls claims court don't need a solicitor and costs do not generally follow the event (meaning that the losing party is not ordered to pay the legal costs of the successful party). There is a small fee to pay to start the claim but this is recoverable if the claim is successful. Attached below is a link to the CAB guide on small claims which provides details on the process of issuing a claim, recoverable fee, interest etc.:
I hope that's helpful and please don't hesitate to let me know if I can clarify anything for you.