Incorrect billing

I am very disappointed with the service that I’ve been getting from telkom, in 2016 I took out a contract which is a laptop and wireless router and my bill was R349 per month but from 2018 I noticed a change in my billing and when I called in they told me that I have an open spend limit which was something that I said I didn’t want, before my billing changed if I’ve used up all my data I’d top it up and buy more data but to my surprise I now had “a spend limit “ active in my acc. I called in more than once requesting this be canceled but it looks that was never done because I’m still being billed more than what I’m suppose to be billed. Today (3 September 2019) I spoke to Nosipho whose supervisor is Tebogo and she was of no help at all she couldn’t answer my calls at all and couldn’t even state when my contract will expire because her system doesn’t show that info.....I’ve been billed more than what I signed up for and now I’m suppose to go to the branch to find out a simple thing as when my contract will expire. I’m not happy at all and I want my money back for all these debit orders that went off on my acc. Please get Someone who understands the EFTs much better to explain what’s happening my number is***