Pillar to Post

I am so disappointed in MTN South Africa my Elderly Mother who has had a Cell Phone contract with MTN since 2009 has been renewing her contract and making payments without fail, The cell phone she received last year 2022 had an issue she took it in, to be fixed at MTN Springs in October 2023 and till date she has not received back it back, she has been taken from pillar to post and no one has answers for her and off course MTN is still taking their monthly debit orders but she has no phone. May MTN Intervene either cancel her contract or give her a phone