Bad service from Cell C again.

Last year November 2019 I sighed a contract month to month for a 10 meg line (10 down/5 up) and the cost was R 599. Now suddenly in July 2020 the increased the price to R 749. More than 20% increase for a service not even more than a year old. This month I received a bill of R 879 and when I inquired about it they said it's the cost for 20 Meg line which I did not ask for. They even threaten to take legal action should I not pay this immediately. Be careful of their schemes and so called specials. They NEVER keep their word or keep to the contract. This is what to expect from cell c although you have been a customer of theirs for more than 10 years. This service is unacceptable and they should refund me for the previous months they ripped me off. When you call them it is like speaking down into the abyss.