Monthly allocation

I've had a cellphone contract with Mtn for the past two years however recently I have received bad customer service from them, I did an upgrade on October 2022 and I was supposed to receive my monthly allocation however it keeps on changing and I've went to their branch at East gate and I couldn't get assistance and I also went to Trade route mall and they still couldn't assist me. I called their customer care several times and they still couldn't assist as well whereas they deduct money from my account on a monthly basis and I'm still not getting my monthly allocation that I was promised.