Worst service ever. No help from anyone

My Mr Price account has been handed over to ACS. For what reason I do not know. I did make arrangements to pay my account off. Mr price was accepting my arrangement. No suddenly I am getting emials and statements with extra charges from ACS. I am trying to call them many many many time. No answer. I am sending emails everyday NO REPLY. IF I call Mr Price they are just saying sorry but your account is with ACS we can not help you. This is the worst service ever. And they are taking my money for WHAT if I had arrangement. This is pathetic for a big company like this.