AimLoan.com used a bad tax estimate when closing my loan and owes me money back from my escrow account. However, they will not correct the problem and have not been timely responding to the RESPA Notice of Error that I have sent them. I have paid the principal and interest, but they will not apply it to my account and are charging me late fees for the whole amount when only the escrow is in dispute. What good is RESPA if the lender/servicer can continue to act in bad faith and punish the consumer at will. Even after the mortgage fiasco that caused the recent recession, the consumer is always left holding the bag and the lenders can do whatever they like with impunity. 
