Yeah, that was my impression too. If they charge me for the past purchases, it’s ok, as long as they refund the original amount to my hfp account. Not a big deal for me, but honestly I doubt that it worth the hassle for them, I am pretty sure that their developers have better things to do.
On the other hand I still believe that the error message is terrible, I can see others complaining for the same thing, they could save all of these complains by providing clear error messages.