DELAYED INVESTIGATIPN COSTING ME AN ARM AND LEG

Submitted a claim on the 8th of February 2021 & got authorisation on the 16 March 2021....a full 6 weeks of investigation. During that time I had to hire a car for a full 6 weeks while they delay forever. I was told 72 hours and then later told of 10 days but I got 6 weeks. Took forever to appoint an assessor and vehicle is still waiting for parts. Over and above that I am now told I have to pay double the excess because I submissted a claim 20 days before they s****ped the double excess rule off their contracts. RIDICULOUS RIDICULOUS RIDICULOUS...how will I afford the double excess when I had to get a vehicle for 6 weeks while they investigate and a further weeks while they repair?