Taking advantage of the pensioners

My mom who is 82, canceled her phone contract, asking that it be a pay-as-you-go line. She called on 31/3/23 when they notified her that the contract ended on 24/4/23. They first offered her a cheaper contract which she said no to but told her she had to do it on a specific date to cancel, which she then did. The following day she received a message saying congratulations on your new contract! On 3/4/23, my mom called again, speaking to an agent called Masilo, who then assured my mom she had canceled the contract, and said that they are going to call her back on 7/4/23 to confirm, which they never had. Then my mom called back on 28/4/23, speaking to Sinethemba, who gave my mom a reference number (Listed below), and yet my mom is being harrassed by calls saying she must pay. She was told to call on 1 May, 23 to confirm, but as that was a public holiday she called on 29/4/23, but they said she should call back on 2 May, which she did (Really unfair to a pensioner!), but yet on 1 June received more data and airtime! She is scared to use any data so doesn't want to leave the house. I tried to call but they say they can only talk to my mom, and yet when she speaks to them they keep ignoring her cancelation and adding more airtime and data, which she is not using. They are still billing her every month and now harassing her for payments. She honestly has no money, living off a small state pension, and after multiple times of calling in to correct it, it has been ignored. PLEASE stop taking advantage of old people.