A similar thing happened last December. Theres a thread on here but i don't know how to link a thread in a reply. It's under "Atco Energy" and first post was Dec 09 /16 Some other retailers such an Enmax came to the party and offered customers rebates. All it took was a call or live chat on their site.
ATCO is trying to be a big name in home energy services. I think that Nancy Southern offered a free month last year if you signed a contract with ATCO. Not sure what they are like to deal with?
Read the fine print, believe only the natural gas portion of bill is free, most other fees largest part of bill still apply.
"All new ATCOenergy customers will receive a credit for their electricity and natural gas consumption in January and February." http://www.atcoenergy.com/home/shop.html