gmac mortgage misapplied payments and payment has increased $300.00 in 3 years on a fixed rate. Internet

I had a 15 year FHA loan through GMAC and I was about 3 years into it. I refinanced and was advised that I had to refinance to a 25 year loan because that was the shortest time they could do it. They had my account so messed up it was not funny. I made a by monthly payment. They refused to apply the payment by monthly and would only apply it once a month. They are still charging interest on the money they had. I could only refinance through them due to this reason. I have a fixed interest rate and original payment of about $730.00 per month. in the past 3 years it has increased to $1130.00 per month. 

My home owners has decreased and taxes are about the same. I send them $450.00 twice a month since I had the loan. I am still behind for more than $2000.00. Again they held the money and did not apply it when it was sent, still charging interest on it. There is not to be any penalties for paying early. Still charging interest and late fees. There needs to be something done about the big companies doing whatever they want to people. How much money are they making off of just not applying payments correctly. At least we are trying to pay them something. I guess $900.00 per month is not good enough for the poor economy.