Appalling Service!!!!!!!!

The service at Vodacom is appalling!!!!!!.I've been paying my modem with them Via Eft for the past year but for some reason they failed to allocate the payment for the last 2 months and now my modem has been deactivated as a result, when I called to enquire I was told that I made the payments earlier than usual so these payments weren't allocated and I have to pay an extra R219.00 to have the modem reactivated. I think this is absolutely ridiculous, why should I have to pay extra because they failed to do their job?????