Vodacom duped me into paying for a contract when i have been on pay as you go for year.

I cancelled my contract with Vodacom about a year ago and settled all that was due. In July 2017 they started calling asking for monthly subscriptions, i explained to them and they assured me that they have rectified their mistake. This meant they had cancelled the arrears. Attorneys or debt collectors called about a different account and i made arrangements. This is when Vodacom handed over the 'written off' account. I therefore made a payment to the attorneys thinking i'm settling the account only to realise that i have been duped into paying for what was written off. Vodacom or Hammond Pole attorneys should pay me back my money.