Account is still wrong!

It seems from my latest invoice that Vodacom has done it again. After having R1404 deducted off my account while expecting to pay R249 because I rang up a bill of R1100 on extra data (While having put in a R50 limit, not getting any sms to notify me that I have run out of data and not knowing I had prorate data). I agreed to buy a data bundle to cover the over used data for R249. I was supposed to be credited the R1404 minus Feb's payment (R259) and the data bundle (R249). Now I see Vodacom has take off Feb's R259 plus the bundle R249 plus R375.31. When asked what this was, it's another R259 plus R116.31 for out of bundle use! So it looks like I have paid for Feb twice. I have done my utmost best to limit this stupid out of bundle use thing. I have the app installed and I have asked to be sent an sms when I run out. I still get nothing! It's like Vodacom is *****ing money from me while smiling at me and there isn't a dam thing I can do.