Door to door and telemarketing ha e the 12 month offers, they are legit. Calling in gets you the mass offer (what they offer to anyone and everyone who calls in or goes to the store).
I would call back and tell MTS that you recieved a 12 month offer from door to door and that you would like it. I have had no issues doing that.
As for the deal, it is basic tv (for 1 tv) and lightning 25 for $55 per month for 12 months. Any additional tvs are $3 a piece, more tv channels will bring up the price as well. If you want THPP, that is an extra $15 per month. Gives you unlimited long distance in canada and us 24/7, and 4 calling features.
MTS can give more details