I got two Storms on Jan 31st. Buy One Get One promo started 7 days later.
At the time of sale, the promo was buy for 199 each and get a 50.00 mail in rebate.
I got both rebates.
Called VZW and asked politely what they could do for me since I had paid full price minus rebate for my Storms.
They looked up the policy, and they credited my account $149.00 so that after the 50.00 rebate, one phone would be free, and the other cost only 149.00
My advice is to call VZW and ask politely if you can get the BOGO offer retroactively, since you signed up so close to the date that the new promo went into place.