Vodacom - poor service

I bought a new phone from Vodacom 3 months ago. In the first week I was getting sms's about someone elses expenditures and bank balances. I informed Vodacom and was told it's not a recycled number. This has been going on for 3 months now so I whatsapp called the person as their profile is on my whatsapp only to confirm it was there number but was cancelled in 2018. I have been begging for them to cancel this number all together and just give me a new number but it seems to big a task for them to do. Perhaps I should cancel my debit order and maybe then someone from Head Office will actually pick the phone up to call and resolve this issue. VERY POOR SERVICE ..