I tried to send Priority Mail flat rate envelopes to 20 domestic and 8 international addresses. Postage was already paid for all the domestic envelopes. The international mail pieces had customs forms and labels created online with the postage already paid. These envelopes had to be scanned individually. Ms. Lee made a big deal about how many mail pieces I brought to her office. I mentioned that the domestic mail only had to be accepted without any administrative work and the international pieces just needed to be scanned. She seemed irritated and made a unnecessary big deal about having to sort the domestic pieces. She created two bins and threw my envelopes in them with a loud bang. In the meantime, she said something about processing the international mail that I did not understand. I repeated that those only needed to be scanned. Ms. Lee seemed upset, stated that she understood that and asked me to be patient (something you should never ever say to a customer), although I don’t think I lost my patience just because I tried to make sure my needs were understood. To accept the international mail, Ms. Lee tried to use a scanner and she seemed to be unable to scan the bar code. She said the bar codes must not be printed well and offered to take the envelopes without scanning. I repeated that I needed them scanned for proof of mailing and I left the office. I drove to another post office where the same labels were scanned without a problem. It was also explained to me there that the bar code can be entered manually if the scanner does not work. Ms. Lee did not offer to do that. I have to conclude that Ms. Lee is either incompetent or she simply does not make a good effort to do her job, perhaps she is intentionally inefficient.This was not the first time Ms. Lee was not helpful. She had asked me multiple times to take my mail pieces to another office. She had also commented on my late arrival to the post office 15 minutes before closing.Ms. Lee’s deliberate and repeated failure to accomplish requested tasks for which she is responsible, her stubbornness, her verbal and nonverbal expressions of frustration are passive aggressive behavior patterns that are unacceptable in customer service. I wanted to discuss this with her supervisor and returned to this office to ask for the supervisor’s name and phone number but she denied my request. Ms. Lee stated that she is the postmaster and she has no supervisor. Maybe Ms. Lee is very lucky but I doubt that this statement is true.Other employees in this office are nice, efficient and knowledgeable. It is unfortunate that the head of this office sets such a bad example.