My thermostat in my home will not stop beeping!?

Please help. as I feel my patience is on the brink. I (a very not tech-wise individual and my very tech savvy roommate have both read the front & back of the manual for the thermostat in our house and nothing sheds any advice on how to solve this unusual problem. My roommate speculated that first, it is probably the double AA batteries that were low & so we replaced with some double A Energizer Rechargeable and nothing got better at all. This persist ant beeping goes on every 30 seconds, this all started on Friday and I figured I'd let the beast run it's course and that it would eventually stop beeping, to say the least it has not stopped at all! I tried twice to call the 1-800 number on the thermostat's manual and got no true help both times. Please let me know what I should do next