Vodacom account overcharged for months

I am posting this complaint on behalf of my aunt, a pensioner who does not have access to HelloPeter:

She purchased a new phone, cash, from Vodacom at the Grove in Pretoria on 3 August 2023. I signed up for a RED price plan, of 3.6 GB and 600 minutes at a monthly subscription cost of R579.

Since then, Vodacom has deducted R1764.36 from her account via debit order every month. Vodacom added account features she never signed up for, like R75 for Red Flexy Billing, and R72 for itemized billing.

After repeatedly raising this issue with Vodacom's branch manager at the Grove, Billy, they refunded R1755 in March 2024. They did not provide an explanation what the reasoning is behind this, or if she can expect more repayments. Vodacom owes her a lot more than this when you consider they overcharged me almost R1200 per month. If we do a rough calculation, Vodacom owes her around R8400?

On 2 April 2024, they once again deducted R1743.50 from her account. She took this up with Billy at the Grove, who said he escalated it to the CEO's office. The feedback he got is that they will resolve this within 72 hours, but after all her previous complaints she is not holding her breath.

My aunt is at her wits end - nothing she seems to do can resolve this matter or ensure that they return all the money they have overcharged since last year. We would appreciate to see the overcharged money refunded in full.