Incorrect Vodacom debt handed over to debt collectors

At the end of my Vodacom contract in 2024, I went on to 'pay as you go'. Around September '25 I arranged for my number to be ported to Afrihost. This was done and I have been using this service provider since November '25. I have been receiving emails, phone calls and SMSs from Burnard Raaf and Associates advising that I have an amount of over R1 000 due for unpaid invoices and legal fees. I have not received said invoices, and there should be nothing owing because I was on 'pay as you go'.