Same here.

I just sent them an email asking about their interpretations of supermarket and gas station. Recently I made two transactions, one at a local grocery store and the other at a gas station, but only get 1% cash back

I am also confused about their rewards system, too complicated (or maybe I'm super-dumb).

这不是变相欺骗吗？

以5% Cash back为诱饵，然后又自己规定什么算什么不算的。