Mtn cancelations department unhelpful or rather non existent

My mom is living in the UK. She has sent numerous emails to stop her mtn account but has had no response. I sent an email on her behalf forwarding her original email and have also had no response. Even if you not able to assist me as the daughter. Would it not be the couteous thing to at least send me an email. This has been ongoing now for over a month. Can someone at least let me know how I can assist my mom to cancel a mtn contract that she is not able to use in the UK. The contract is currently on month to month as the original contract has expired.