Price increase without reasoning

I have taken out an uncapped 100 mb fibre contract with Telkom for R899 a month. A couple aof months ago my debit order changed to R945 without any reasoning behind it , I thought my contract had elapsed so I visited a Telkom branch to look at my options and was advised that my contract was still active, upon questioning the price increase nobody at the branch could give me an answer and told me that their sales department would contact me , to date we had one phone call where my wife was placed on hold and the call cut.

We visited the branch again and was advised the same thing but still no contact.