Paying R800 for a R200 plan!! RIDICULOUS!!

On the 12th of April at 10:36 I called Telkom 10210 to cap my calls to R300 and was advised by a lady that it was done. 2 months later I received my bill which shows it wasn't done. I called customer care on 12 June to enquire and was told there is no call proof that shows I had called in and requested for spending limit cap.