iPad doesn't recognize my Apple id - Can't use.

Forgot my password. Took it to the Apple Store to reset. Went home and followed their instructions to enable it with instructions that would come when keeping it next to my iPhone. All was fine until it didn't recognize my username and password. Message comes up titled ACTIVATION LOCK This iPad is linked to an Apple ID an'ad password that were used to set up this iPad. It continues listing the email "mxxxxx@xxxxx.com".

I've owned the iPad since it was taken out of the box at work for me. Serial # is **********.

Any advice to get it working?