Does the Post Office have the right to stop delivering my mail?

I live in a condo complex, and the mailboxes are located in the vestibule on the first floor. Working 2 jobs and some days 7am - 10pm, I don't always stop to get my mail. Two weeks ago, I noticed that my mailbox was empty, and in the following 2 weeks, no mail was being delivered, and no notice telling me why, or what to do from that point. After the President's Day holiday, after work on Tuesday, I stopped at the Post Office and was told that my mailbox was full, therefore delivery had been stopped. Which meant my bills, mortgage statement, tax information, etc. was being held hostage by the Post Office. The clerk at the PO stated that the carrier decided she was not going to deliver it anymore. Is this legal? I feel this is a huge violation of my rights.