Cell C Really Now??????

Good day, I have problem with Cell C. On the 30th November 2020 I called and i enquired what the balance is in order for me to get an early upgrade. I was advised that it is R2793.88. So there was a problem with my bank where all by debit orders bounced back, but than on 3rd December 2020 made payments, one for R2400, R200 and R100. Take in mind that I'm aware that my installment of R459 that bounced should be deducted from that amount aswell. According to my calculations I should be left with a balance of R552.88. I add the payments that i made altogether R2700, than i deducted my instalment that bounced R459 so i lm left with R2241. So than i deduct R2241 from the balance that was given to me which is R2793.88. So i should be left with R552.88. When i called again asking to confirm the amount that is due, they first said nothing is reflecting. I send my proof of payments. I called again this morning and the consultant said i still owe R1100 and some change. She couldn't even explain to me whey that is the balance and was talking about March month when my debit order also bounced back and which i also made a transfer the same time. My account was up to date when i called for the balance. Now they are giving me the runaround.