put your attempts to contact in writing, preferably from an attorney's office. That is, write an actual letter and have it delivered with a delivery receipt (certified mail) so you can prove you sent it and, hopefully, that he got it. keep a record of all phone calls. if you simply call or try to go by the place, it is your word against his that you tried to contact him within the required time frame. Also document the date you first noticed the problem, any expenses, etc.