Impossible to get ANY assistance from Telkom

At the end of February, I signed up for Telkom's LTE 40gig plus 40gig special. However, only 20gig anytime data is allocated to my account, instead of the advertised 40gig anytime data. I have tried, at all hours of the day, to get help via the call centre. NO ONE EVER answers, regardless of how long I hold. I have tried all avenues on the Telkom app - e-mail, chat, call me back, all to no avail. I need help, and am frustrated beyond words with Telkom's non-existent service. What is more, I noticesld that I was charged much more than the advertised amount for my April account. What can I do to get assistance from Telkom.