Poor service and *****

Good afternoon

I app**** for a contract for a laptop at vodacom last year in August, they send me a notepad, I had to send it back to vodacom because they gave me incorrect stock, and vodacom confirmed that they got their stock back and confirm that using the tracking number that RAM provided me with, I called vodacom to cancel the contract and that was within 7 days. They deducted amount from my bank account but it was refunded , now i received a letter stating that I owe vodacom amount of R2 932.40 and my account is with Debt collection agency, i tried calling their accounts department I spoke to Matshindiso Mnkuni she told me that she can't help me bacause my account is with the legal team and I am instructed to pay this amount.

I am confused because how can i pay for somthing that I don't have, and I cancelled the contract with vodacom within 14 days, Please assist .

Regards, Philile