Account switched to non-premium [ SeanyJo ]

Hi, my problem is that whenever I've been trying to connect to multiplayer servers lately, I get the Failed to login: Bad Login message. This happened off and on. Then, this morning, when I tried to logon, it said that I haven't bought the game. Recently, I have migrated my mc account to mojang, and have still been using my mc username to log on, and it has worked fine. The Bad Logins started happening after I changed my password for my mc and mojang accounts. My username is SeanyJo.