Vodacom is unfair

I have been under debt review for more than 4 years and not once have I had a problem about that by Vodacom

I received the Vodacom statement on the 7 Jan 2020 and the amount due was R 3 178.44, and that was paid on the 27th Jan 20. I paid as per the statement, on Saturday 29 Feb 20, I went to Vodacom Alberton City , to find out that there was a flag on my account for ± R 100.00, but I paid the account asper statement, the debit order was reversed by me due to another problem that I was trying to sort out, but I asked if I could make and EFT and that was, but the debit order was reinstated for collection on the 27th Feb 20 and it was collected successful, now I can’t upgrade after I have done the payment,

I have a problem due to the fact that I have been under debt review for more than 4 years (I Have asked to be put under debt review) and not once did Vodacom have a problem with it, BUT NOW they have,

I need in writing why VODACOM management (NOT A PHONE CALL) never had a problem until now, and all due to a sully ± R 100.00, REALLY

I am asking to sort this out ASAP and allow the upgrade