Purchase any size Froster, and get a refillable mug for free with this printable coupon from Mac’s Convenience Stores Ontario. Also, when you use your refillable mug, your first fill of a Froster is free! This offer is only for residents of Ontario only and is valid for the week of February the 15th to the 21st, 2016. There is a limit of one offer per person so Mac’s asks that you print the coupon only once. The retail value of the free mug that you are getting is $3.49 – $4.49.