Mvia warranty

Hi I have put a claim in December in January a assessor came through the work shop to inspect the vehicle. I received a mail the next day to say rejected because of modification no reason given to the modification I have emailed complaints and resolution department to take this up I also been calling the call center numerous times .I received a email to say the matter has to be investigated and there's no number for that department can only correspond by email.Yesterday called the call centre again was told by the supervisor that the investigation takes 45days that the first I heard of a Insurance company taking this long.I told the supervisor wen a customer take a product with your company they dnt say things like this and every month I am paying my debit .I just feel I should get a lawyer to fight this because they are wasting my time and this company lies to the customers especially wen you make a claim