MTN 's loyalty to their customers

I have been a loyal customer to MTN for almost 25 years. Unfortunately due to the pandemic, we have had to take salary cuts and business has declined so my commission is extremely low . My debit order was returned this month (I take full responsibility for that happening) but what has really shaken me is MTN's response. I have tried numerous times since last week to contact the call centre to discuss my debit order with someone and I keep getting a voice message 'we are experiencing temporary network difficulties'. I have sent an email to the customer care email address with no response. Over the weekend I received two emails from MTN telling me that my contract has been cancelled and I owe them almost R10 000.00. Really? I'm battling to buy food and they want me to pay R10 000.00, Good luck with that!!!! I am so dissapointed in MTN - my debit order has been returned once! If this had been going on for 2-3 months I could understand, but their reaction is beyond my understanding.