MTN ONLINE IS A ****

Good day

I bought a Wi-Fi router at mtn online on the 12.06.2025 The router did not work then had to return it to the store for a cancellation, until today the contract has not been cancelled and Mtn tried to deduct R2499 when I ask the consultant, she responded that Mtn is deducting for a router.How do they deduct for a router if I returned it on the 12.07.2025. since then, I am struggling to cancel the contract and now I have to change bank account because of their ***********.