account locked due to high data usage

My account was locked earlier today, I contacted Vodacom to find out why on earth my account was locked. The response: That due to high Data usage my account was locked. I have had an account with Vodacom for many years, first in my personal capacity and then in my business. The data usage that they considered high has been more than double the amount it currently is in the past. My account is paid via debit order and is always paid on time no matter what the amount. I was then told it would take up to 24 hours to be unlocked. I receive an SMS once my data bundle is finished and in that SMS it states that out of bundle rates now apply which I accept. So please explain why you decided to lock my account.<br>