Angry customer

I am not very happy at the moment, I signed up in Jan of this year When I signed up I was told an amount that I would need to pay each month I was then able o pay the full amount I sent a message asking what the total was, so that I could pay at the end of Jan. I received and amount which I paid. Then on the 15th March, after asking numerous times, I was told that the amount I paid was incorrect. I was also told that it was my fault that nothing had been done and if I wanted my name to be cleared I needed to pay more. I was also told that I supervisor would phone me. It is now more then 10 days later and I am still waiting. Is this how business is done because if so I will be taking this further.