MTN *****ing from the Elderly!

MTN, *********** the elderly! I have been trying to cancel my elderly mothers cell phone contract for 7 weeks with absolutely no luck. She is now in a carehome with advanced dementia unable to use a phone. I have power of attorney over her affairs. Despite visits to a store, many emails and phone calls, no luck at all! She only gets a small SASSA pension and MTN is quite frankly *****ing what little she has! Disgusted by their inefficienty!