Telkom *********

I had a cellphone contract with Telkom in 2017, from the first month I was over charged, hughlighted this to tme n they promised tomsort out, happened in 3 consecutive months until I told them I'm gona stop the debit order untill this is resolved, my account was suspended due to me stopping payment still with no refund on overcharges, in December there was a data bill of R2,800.00 on suspended account, I asked about it and got told I used the data and have to pay for it, how does one use suspended account, I provided account recon and still they did nothing and put my name bad credit bureaus as a bad payer, how do i get this resolved, its been 4 years now with no help, lots of calls and emails sent but nothing is done, how do we let companies like this to continue operating?