Supersonic - Worst service and be careful with billings!

I've been with Supersonic for about a year and a half now. I've been overcharged every month for the entire time. I'm suppose to pay R599 for a 25mb/25mb uncapped line. I was charged anything between R650 and R699 every month, every month it's a different amount. I then eventually got it sorted. I then asked them to please remove the debit order so that I can rather pay it myself as I don't trust them. I'm still waiting on confirmation that this has been done. I just dont get any reply to my email. I also received my invoice - I paid on the 26th of July (debit order) and then got a invoice for the correct amount of R599, but it's due for the 1st of August, so now the date is incorrect, not to the mention the address as well. It's a struggle and then I threatened to cancel my contract, they had the cheek to tell me, I will have to pay claw-back fees after over charging me for 1.5 years. What a joke. Maybe, someone will come back to me now after this post.