Yes I thought so too when it happened with me the first time and because of that I went through the torture that is to remove and then add all my cards again on HDFC Billpay, this time setting Auto Pay and Debit card e-com limits to their maximum of 5L each. Sometime after this I got a bill for ~96K, it got scheduled and then on payment day I received a similiar (not exactly the same) message as the guy you replied to:
There is nothing wrong with the debit card itself because 2 days after this I had another bill scheduled of ~9K which went through just fine.
I have been trying to find a reason for the same because my bills do exceed 1L even for some months and I don't wanna lose the CB for them again.