Went into tk maxx today to look for a dress for a may wedding. As i entered the store there was a lady doing a sponsored bike ride (stationary exercise bike) for cancer research, so i dropped some loose change in the bucket. Also at the changing rooms there were raffels etc and various characters interacting with kids etc. Anyways i was paying at the till and used my contactless card.... the cashier asked me..... if your feeling generous would you like to add £1 to the total in aid of cancer research. I replied no thank you....... she then pulled a face. 
Out of pure embarrassment i told her i had already donated by the front door. I got zero reply ... she just handed me my bag. No thanks..... good bye...... nada. AIBU to expect the staff to be polite and courteous whether i donate or not? It really got my goat and i felt mortified thatcothers were judging me. Had a very lean paychecks recently and i need to watch my pennies!