Poor service and working with **********

I took a contract with Vodacom about 2 years back and when it elapsed, I cancelled it. But Vodacom still insisted i was owing money though I had cancelled. I payed the money anyway and sent a proof of payment but Vodacom is still harassing me today about outstanding amount. I then went to the store 2 months later to enquire why i am still getting calls from Vodacom, they said I am still owing. the people calling me were debt collectors but Vodacom claims the account was never handed over for collection. Vodacom is therefore leaking my personal information to the third party because they seem to have all the details. Vodacom never answers their line when i want to raise such issues. Worst Worst Worst. Vodacom to date owes me R478.88.