You have 14 days from activation when you activate(which would change your data plan) to revert back. So just dial 611 after you activate the phone and they'll convert you back.
I'll keep that in mind. I've had to do it before but it was uning another line's upgrade on the account to get the phone. The online oder showed the $15.00 data in the "old" column and in the "new" also with no change and no choice of the data plans. But I'll keep your tip in mind as I rarely even come close to using my 150 MB limit.