Billing of R500 more

27 Jan 2020 I upgraded to a sim only plan which would be R299 p/m; the last few days of Jan were charged prorata which came up to an amount of R179 on my billing statement for end of Feb. I then received my billing statement for March and to my shock it said my bill is R799. I called Telkom and the lady I spoke to said I had out of bundle rates on my contract and I advised that she please set the out of bundle to R0 as I am fine with the data I get. She assured me that my next bill would be corrected at R299. Sunday 5 April, I receive my bill and again the huge amount of R799 awaits to be debited, even when I was reassured by the lady, that this would be sorted out. Not happy at all with this. Telkom please sort this out ASAP.