Trying to recover old phone number

My old home phone number - which I've had for over 15 years - appears to be in some type of limbo and no one from AT&T seems to be able to figure out how to reassign it.

Back in late August, I had an appointment to move my AT&T Uverse, Internet, and Home Phone to another house in the same neighborhood (we were moving to a new home 4 houses down the same street in Orlando, FL). The technicians were in the middle of hooking up the new service when I had to cancel the appointment due to a family emergency (my live-in father-in-law, who had a massive stroke 3 days before the install, was in the hospital in a coma, and took a turn for the worse that day. I should have cancelled the appointment all together but we had relatives who flew in to see him and I didn't want them to not have any TV or internet while staying with us).

It took me a few weeks to setup a new appointment and I was told at that time that it would be easier to create a NEW account at the new house with a temporary phone number and that I could always change back to my old number at a later date.

Since then I've been on the phone with customer support numerous times over the past few months, speaking to various departments (tech support, phone sales, and I think what used to be Bellsouth). When they look up the old number, they say that it is somehow locked and can't be reassigned. The closest I got to a resolution was a kind woman who I spoke to just after the holidays that sympathized with my situation (and that my wife is desperate to have this number back). She was determined to see why this number couldn't be released for reuse. She assured me she would be submitting a ticket to have it investigated further and that she'd contact me again to be sure it was reassigned and working properly. That was 3 weeks ago.

Can someone out there at AT&T help? When I call my old number, I get an automated response that, "you have reached a number that has been disconnected or is no longer in service," - which tells me that the number hasn't been reassigned to anyone else and must somehow still be available. Please help!