Breach of contract? Hoping nobody notice R10/month?

Upon wanting to cancel my contract last year, I was offered a deal over the phone for a monthly rate of R125 flat. I specifically asked whether that will be the total amount and that call identity, etc. are all included in the R125. The person on the other end confirmed it. (It was recorded for quality and control purposes for what it is worth). The montly deduction ever since the upgrade is R135. Are they hoping that nobody will complain about R10/month. This is *****ing and breach of contract.

I sent multiple emails to vodacom customer care, but not joy up to now.