URGENT! VERY UPSET CLIENT!

I went to the Tygervalley Mall branch on the 29th of March and dealt with Mark. I asked Mark to change my contract to prepaid as I am wanting to port to Telkom at the expiry of my contract. Mark advised me that my contract expires at the end of April and that my phone will then be converted to prepaid. On Saturday (the 2nd of April) my phone was cut off by Vocacom completely! I phoned their Contract Centre only to be told that, yes, it was cut off and will only be changed to prepaid as from 1 May, as this is when my contract expires. Meaning that I must pay my full bill for April but that I will have no netword for the whole month! Are you insane??? How can you do this to a customer??? I am now stranded without any means of communication while they are trying to fix the problem, all the while still paying for the service! I am shocked beyond words!