SHODDY DSTV

I cancelled my dstv subscription at the end of November 2010. As it was late they debited me , but a received a refund 8 days later. I assumed all was good. On 29 th December I received an SMS from DSTV saying they would deduct 2x subscription on 2 Jan 2021. After a long frustrating dialogue with various players, I finally was told that it was a mistake, I was disconnected and I owed no money. I asked the person for an email which she sent, confirming what was said. On 2 January 2021 they deducted 2x my subscription. I fired off an angry e mail. I received a mail this morning saying a refund has been captured and I "should" receive a full refund within 7 to 14 days. I am frustrated. I am a pensioner and do not appreciate my limited amount of money being tampered with. Why should I have to wait 2 weeks? Note that the mail says " should" . There is no guarantee. How do I know this will not happen again? Why should I be paying bank charges for their mistakes? This is really shoddy service