MTN- Playing with People's financial wellbeing

I am extremely frustrated with how this situation has been handled. I settled my outstanding debt with MTN, even paying a little extra, and received a paid-up letter from the collection agency. They assured me that they would communicate with MTN. Now, over 40 days later, I’m being told it was my responsibility to submit the letter to MTN. This is despite the fact that I’ve been emailing both SAYA and MTN since receiving the letter, with no response from either. The lack of communication and accountability is unacceptable—people's financial well-being should not be treated this carelessly.