Bad communiction from Vodacom with costumers

I had data contract with Vodacom and last year around October discovered someone did an upgrade on my account and money was deducted on my bank account. Logged the query the ***** query with Vodacom. And Vodacom put my account on suspended while investigating. Vodacom returned the deducted money. Now i am receiving calls that my account is arrears and being handed over to debt collectors. Calling debt collectors they sending me to call Vodacom and Vodacom says i must speak to debt collectors.