No Sympothy

I've recently ran into arears with vodacom as my bank was the problem. They didn't send me a sms to say how much was left in my account and that there was a unpaid debit. I contacted them to tell them what went down. The operator told me its fine and she'll make a note. On the 21th of April they decided to block the sim and with no notification. I phoned them to ask them what was the reason seeing that I explained everything to the operator on the 3rd of April. Cause by then I saw what has occured on my account and immediatly changed banks. So explained myself all over again but the operator told me that they don't notify you. The thing that bugs me the most is why didn't they block the sim earlier as no payment was received then it would have came much sooner to my attention and could've rectified the promblem sooner. But I was under the impression that all was sorted and that I could pay the outstanding with the new bill at the end of this month...... So I'm unhappy with there process. As its not even my fault.