Android Device Manager Lock

My phone was lost and I administered an android device manager lock I have went in the manager and changed the password several times as well as entered it on my device which as since been recovered by the person who had it in their possession. I do not want to have to master reset I do not have my current information backed up as of date, so I would be losing quite a bit of information. Is there anything I can do I called T-mobile the so called tech said wait 72 hours that sounded like bs that the phone would magically start accepting the passwords entered. The message being given to me by google is that a password lock was already on the phone which is not correct I never had a password lock screen on the phone prior to losing it. I also was not signed into the samsung account portal so can't use their unlock feature is there any software here I can download maybe reflash firmware that won't effect my current data but remove the lock screen? Let me know thanks.