MTN Business Fails to Address Contract Loading Error

I signed a 24-month contract with MTN Business and have retained the original letter, order, and email confirmations. Nearly two weeks ago, I reached out to upgrade—my upgrade being two months overdue—only to discover that my contract now reflects a 36-month term, obligating me to pay for an extra year. I was informed that an error occurred during the processing of my contract and that it would be resolved. However, I have not received any follow-up, and my invoice and debit orders are still being processed as scheduled. This is entirely unacceptable, especially considering I hold both a personal and a business account with MTN.