Pathetic service - does not keep promise to client

I received an call beginning July about my payment that I did make as I do every month and I was charged with collection fees that was not suppose to happen. I logged complaint on hellopeter and got e-mail from the manager and he promissed to remove the fees, BUT NOTHING HAPPENED. I got the same call again on 3 Aug and I had to go through the whole discussion again where the agent promised me an e-mail as confirmation when he checked in with his manager and to remove the fees, nevertheless I received my statement today and the fees is still there and my acc reflects now as in arrears. I do pay my installment every month without skipping one payment and when I phone the company I get NO FEEDBACK AND NO CLIENT SERVICE so what more can I do must I stop paying the acc, because I am currently working only on contract basis and strictly do not have the money to pay the installment, BUT I still do. How can you promise a client something and do not deliver on a promise and mess up my credit record?