Prepaid plan Activation Problem

So I am currently in the process of switching both phones and companies from straight talk to AT&T.  Im going from a galaxy luna pro to a note8 that has been used for AT&T service before.  I bought the bring your own sim kit and 45$ prepaid plan which arrived a few days ago.  I put the sim in and followed the given instructions and over a day later the note 8 still doesn't work.  I cant make calls or texts of any kind.  My old phone still works, despite straight talk's own site telling me that it is now deactivated.  att.com/activateprepaid tells me that the sim card is active with my phone number being the one I am transferring over with the 45$ prepaid plan.  However, https://att.com/myprepaid wont let me login using my phone number with the last four digits as the password.  At this point I am thoroughly confused and any help resolving the matter would be most appreciated.