Vodacom phone contract

Me and my wife bought two contract phones with Vodacom now the contract is over, they told us to call a certain number to cancel the contract and we call several times almost 6-7 times asking for one thing with no help. So one day my called and the guy that was helping her refused and activated something else we did not ask for and they keep sending us airtime ,data and they texting us saying we owe them. Even after that guy had activated all that we still called to cancel with no success.