Horrible service from Vodacom

Vodacom blacklisted my wife she cancelled her contract the next day she take it out. it was cancelled according to the sales people but they keep on contact her and send emails to tell she's behind and she needs to pay. We had all several documents to proof it was send to Vodacom account department and still they went and blacklist her. it was horrible service if I had a choice I not use Vodacom and also recommend all family friends and colleges not to use Vodacom.