Vodacom

I have had a CONTRACT with Vodacom for 30 years.After my husbands passing in September 2019 I requested his contract to be cancelled(It had already expired)Nov 2019.After numerous phone calls, emails, the contract was eventually cancelled after 13 months. Vodacom traced my original call and promised to refund me as we never used the phone since his passing .Up to date nothing has happened. About 3 months ago my mom complained that she never had any airtime on the contract I have been paying for her the past 8 years. I checked her statement and noticed that we have been paying BBM(Blackberry fees ) for the past 4 years,needless to say,she replaced the Blackberry years ago(an upgrade done with Vodacom) On complaining the assistant was very rude and I requested his supervisor to phone me.Up to date ,it hasnt happened. What am I to do?