Pathetic service

I have 3 accounts with vodacom. I called them to block the one sim, in march, becaue the phone was lost, which they did not do. I called again after a month, after i received a bill for this sim, they then told me it never was blocked!! So they said they did it again, but it still wasnt done, only after the third time they actually blocked the sim!! They then said they will do an investigation as they have to credti me for that money, as i didnt use that sim card, this was 2 months ago. Today when i called them again, they said i must give them time until 1st of may to do an investigation, for something that shouldn't be so difficult! This is utterly pathetic and poor service once again from vodacom!!! I refuse to pay for something i didnt use! If this isnt sorted out i will cancel ALL my companys contracts