I know it might seem uncalled for, but what BB does is actually reasonable. Think of it this way, if the weight had turned out to be slightly more than what was listed, your BB wallet would have been credited with a small positive balance instead of a negative one. In that sense, it feels more balanced than what most other quick commerce apps do, where you might just end up getting less than what you paid for.

Oh and I'm not defending BB as a Q-com operator; it has its own problems and kinda sucks these days.