Refund

I recently went to a Vodacom store and paid the remaining amount on my device I was advised that I can only call in on February to cancel my contract. Which I was fine with on the 20th of this month Vodacom debited me R1000, I contacted their call center to find out why I was being debited when the contract is paid up. I spoke to a lady named Prudence asked her why am I being debited she advised that the system noticed the error and my account is now in a positive which means I will not get debited going forward. I advised her that the contract is paid up and I should not be debited, I was transferred from pillar to post afterwards with no solution, the last lady I spoke to dropped the call and currently I am very frustrated and I want my money back!