RCS Pathetic Customer service

I had a personal loan with RCS and have been struggling for 3 weeks now to get a Settlement amount from them, every time I managed to get a response from them the Settlement amount was way out of line compared to my outstanding balance. Besides the fact that they are Very unhappy to talk to me about a Settlement, without any courtesy or manners. Now, after paying the Settlement amount, I'm strustruggling to get an account closure letter out of them. Please also keep in mind, Before anyone gets a loan with RCS, they charge a Rediculous interest rate of 27%