BAD SERVICE, STILL ALLOW LIMIT TO EXCEED

I have requested for a limit on my Ipad a couple of months ago. On the 23rd of March I received a mail advising it's standing at 345.77, today my debit order went off for this, they deducting over R 4000!!! Where the Ipad has hardly been used from the 23rd to current! Why do I have a limit if you still allow this??? I have phoned and now been holding for 25 minutes and still nobody assisting me!!! Is this the kind of service we should just accept in this country? I will never, but never do another contract with Altech and will not use this contract going forward, you have just made the last money from me! contract number is ***.