Appalling service provided by call centre agents and team leaders

2 months ago I requested a package upgrade from Multichoice. I've called the call centre more than 5 times and have been told its pending all this time. Two debit orders were taken from my account and I was told the 2nd debit order is the difference between the two packages I'll have access to my new package in an hour. it's been a week since and I still dont have access to the upgraded package. Agents tell me they will ask team leaders to call me back and fix the issue. It hasn't happened for 2 months.

To whom do I escalate this issue?