Unwilling to handle TP claims, do not respond

One of their clients damaged my car in Oct, they will not handle my Third Party claim.<br> They do not return emails or telephone calls<br> <br> I have tried about 20 times to get in contact with them and they seldom answer the telephone calls, when they do I get transferred to the Third Party claims where no one answers the phone for over 20 mins before the call gets cut