Sales clerks who say..."No problem" in response to my "thank you." Of course it is not a problem....it is your JOB. Neither "no problem" nor "have a nice one" ....I always wonder a nice WHAT... is "THANK YOU"....

Sales clerks who carry on conversations with each other while attending (or not) to the customer. That is rude.

Sales clerks who do not greet me. I will wait forever until they say something.

Change on top of the bills. Do sales people not understand how much easier it is for the CUSTOMER to handle when the coins are placed in the hand first....then the bills?