VOX Overcharge

I have unsuccessfully tried to speak to someone about a query I have on my account on multiple occasions. Your Accounts people just can’t help me and keep transferring me to an “Accounts Manager”, that doesn’t seem to exist. I logged a ticket and nothing happened. No one even tried to contact me. In February I upgraded my account AFTER my payment for February which was R708 on my old plan. Was 9th of February if I remember correctly. I was then promptly invoiced a Pro Rata of R569.16 for the remainder of the month. My account total that I paid now for March was R1447, which is my new plans amount of R878 plus the pro rata of R569.16. This is a clear overcharge, because what happened to the R708 I paid on 1 February. Was that even taken into consideration when you worked out how much my pro rata should be? Or are you guys in the business of ****ming people’s accounts??? I expect someone to phone me and please explain what Vox did with my account and why I’m being overcharged.