Telkom billing and client service stink

ADSL Line ********** 659 I upgraded in October 2018 from Basic to uncapped and was told my monthly payment would go up to R605. The next bill was over R1000.00. For months now I am trying desperately to sort this with Telkom. By phoning billing department numerous times and going to the store and speaking to a manager. Everyone says that there should be no penalties when you upgrade but does anyone ever fix this?? No! Always same answer we will sort this but nothing ever happens. Latest bill in Feburuary 2019 is R1 800. I am so sick of Telkom .