anyone has auto-billing with advance payment problem?

i've enable the autobilling for my streamyx account, so i have made a payment on 6-June (for amex 5% weekend), but then the autobilling payment from TM doesn't check whether there's excessive payment in the account, and billed to me another RM150 to my amex card on 13-June... so that consider double payment already...

i remember last time i did the same, and it doesn't trigger the auto-billing one... so i wonder if there's a cut-off date like 2-3 weeks before?