MTN a RIP-OFF?

MTN?? Really? My partner of 30 passed away in 2021. His cell phone contract with MTN was paid monthly through a debit order on my bank account. I travelled to an MTN store a month after he passed to ask that his cell contract be cancelled and was advised that they required a desth certificate (not an unreasonable request). I called the attorneys dealing with his estate and they immediately emailed all details to the store and they received it as I was standing there - I was assured that everything was in order!!! For 18 months AFTER this MTN still deducted the contract amount from my account, despite dozens of calls to their 'service centre' asking and pleading them to stop. I was promissed the best attention and service at all times.....BUT NOTHING HAPPENED! My bank could do nothing as they said that only MTN could cancel the debit order....REALLY MTN is this how you respond to your clients? I have tried for almost 3 years to get some sense and a refund - BUT NOTHING! hundreds of emails and calls - they refuse to assist me .....