I test everytime, njo matter whether I re-order the same type of pill, coz who knows right.
I dont even ask, I just open up my bag and do it, then show it to them. Actually my dd, asked me to test a new batch he had just picked up. They went orange and he was pissed off and running back to his dd for his money back.
But yeah If i get a dodgy one I just say sorry mate these are crap, These are not what I asked for therefore Im not paying.
And I've returned bad ones on several occasions and swapped them for better ones.