Telkom complaints

I opened a 20GB day and 20GB nite contract 2 years ago and up until to date they have been giving me 10GB yet im paying for 20GB. I have been complaining with no avail. Last year a consultant from telkom phoned me and offered me 20GB topup as a courtesy service which i refused but they opened as the new contract and they deducting R349 for it.. Since January they have been deducting over R2800 each month which i will reverse with my bank but now because of Covid-19 i cannot reverse debit orders anymore.. I have been calling them numerous times but i am not getting the assistance i need.