Regret joining them biggest mistake ever

This company is the worst. I was told by one of there presenters that the installation is free, it won’t affect my credit score and I can cancel at anytime. But it is all the opposite. A few weeks after I had it installed I had to cancel it because I had an accident and my car was written off. These people continue to debit even after I emailed them multiple times to request cancellation. My credit score is bad because I keep on reversing the payments. You have to hold for 15 minutes before actually speaking to someone that is of no help at all. They also said that it’s a 3 year contract that I can not get out of and the first payment is double the amount because of installation.