Poor service

I'm not happy with the service I'm getting from them. I migrated my package to a lower package and I asked the consultant several time how much is my new subscription and it was told it's going to be R2 500 for the month on August. To my surprise I received my statement it's showing R4 400. Where does that amount come from. I called and asked for a call recording and now they are giving me a run around. I'm not going to pay that amount, that's not we agreed on. They say they will get back to me and no one does.