Dstv commercial charging for discontinued channels

We have a commercial account with multichoice. We pay extra per additional channel. We noticed that were are still charged for MNET Edge and Animal Planet. These cannels were discontinued by Dstv. To contact DSTV Commercial is fruitless. E-mails, phone calls etc is useless as you dont get through to the socalled non existing billing department. We were given incorrect numbers to dial by the contracting department and even incorrect e-mail adresses. We were cut of numerous times.