Perhaps a less defensive approach may work better for you? Worth a try I would suggest.
Just because its been going on for 18 months doesn't mean that it will go on forever. Billers know their systems and the trends. Whats happening here is definitely an outlier. Banks do as well.
With regard to the BA comment: Perhaps I wasn't clear. There are multiple parties to an online transaction like this. The Biller, A Gateway, A merchant acquirer and a bank. Some of these things are handled by one company and some are not. Some have visibility and some do not. Sometimes the gateway, the acquirer and the bank are the same place and sometimes not.
Having said that, in this value chain businesses make money doing different things. The gateway charges a "click fee" or transaction fee. The merchant acquirer charges an MSF (Merchant service fee) which is a flat fee not a percentage because they are deemed to be a utility and this over rides the interchange on your card.
Looking at this from an economic perspective, the biller is well underwater with this arrangement. The bank issuing your card (BWA) is well under water with this arrangement too.
The gateway and the acquirer are the only ones making money. The acquirer will also have to manage chargeback risk more closely which may well be the trigger. Multiple small transactions are a red flag. Maybe not today but it will happen.
As I said in a previous post, Banks may take time to discover these things but they always do. This sort of thing has been part of my banking career for a long time. My favourite is fraud and Ponzi schemes with ATM deployers. This is not fraud though. Just dodgy.
Bank product managers must manage a profitable portfolio. The most expensive part of this product for them is the points. It will get focus.
Read the items above. Perhaps theres a clue as to my background? Perhaps I could just email the product manager for this specific BWA retail product as they are on my linked feed and get their direct opinion but realistically she already knows.
My point is simple, Make hay while the sun shines and don't be so defensive.