Fed up with Multichoice

First i struggled to get my dstv installed. Now I'm struggling to get my subscription corrected. They told me that my subscription would be R799 / month on a 24 month contract. When i checked my account i saw that it's R918. I wrote to them. They phoned me and acknowledged that they made a mistake and would be corrected in 24 hours. It is now 72 hours later and it's still not corrected. I wrote to them again but it's seems that they are ignoring me.