Vodacom Upgrade Department - Useless Consultants

I have 3 contracts with Vodacom. I have been a client for more than 15 years and always encounter issues when I upgrade. Last year June 2019, I upgraded one of my lines which was a Flexi 125. This package included 125 airtime plus 1GB data monthly. This contract is for my mum. Since the upgrade, my mum has been complaining that her airtime gets finished extremely quickly. My Mum went to the Vodacom shop in Phoenix(Plaza) Durban to query but the consultants keep on charging her R70 to check her device but never resolve the issue. I called Vodacom to query and they advised to restart the phone, switch certain apps off but still nothing. I then called Vodacom on the 06/01/2020 only to find out that the 1GB data was never activated on the account. My mum has being inserting more and more airtime but never knew that she is not getting the data. The consultant I spoke to, advised that they can only activate the 1GB from Jan 2020 and cant back date the data. I was not impressed and asked that she consult with a manager. She came back to state that they will back date the data for 7 months BUT the data will expire at the end of Jan 2020. My Mum will not be able to use 7GB of data in 3 weeks. I was not happy with that and I requested to speak to a manager. I was on hold for more than half an hour and was put to the retention department and soon afterwards the call got cut. Vodacom has unprofessional agents working with limited knowledge on customer service. By putting me to another department and cutting the call does not make me go away and forget the query. I want someone senior to call me and resolve this issue to my satisfaction. Vodacom needs to acknowledge the inconvenience they have caused to my mum. I want a reimbur*****t that is fair.