Multichoice billing

Multichoice billing team is frusrating me, i called them several times regarding my bill because i was told that my bill will be R500 for 24months all of a sudden they are charging me R713 and they are telling me different theories regarding this and they promise to reverse it but it deducts the same amount, on the 20th i called them because i notice that debit order didnt went thru to arrange and the guy who was assisting me told me not to worry because i have a credit so they took that credit so no need for me to pay but guess what they disconmected my services I called again today this morning to find out exactly whats happening they escalated the matter to the team leader by the name of Nwabisa she promised to call me back at 11am today shes going to listen to my conversation with the agent guess what no call till now i called again and no one knows a team leader by the name of Nwabisa and they told me they dnt keep track of the conversations, this is tiring me please assist me on this matter