American Express Membership Rewards - Upgrading AMEX Gold To Platinum--Do I Get To Keep Bonus MR Points Promo?

I am on the verge of upgrading my AMEX Gold Rewards to Platinum in order to take advantage of the travel benefits and a 15,000 MR bonus offer. I am in the midst of a promo on my Gold that gives me double MR points on all online purchases made through the end of the year.

Does anyone know if upgrading to Platinum will wipe out the bonus point promo on my Gold card or will I get the bonus points for everything I’ve purchased up to the point of upgrading? I would expect to lose it for the remainder of the promo period (with the Platinum) but I was wondering about the several $1000's of purchases I’ve already made over the last few weeks (with the Gold).

I’d call customer service to find out but I would probably end up throwing my iPhone against the wall in frustration after trying to get an answer from the India call center

Email through your account summary page on the amex website; written records are always preferable to oral communications (plus you won't damage your iPhone:))

Also, you might wait on the Plat until you can get a better deal. In the past few months I received two (targeted, non-transferable) 25K MR offers to upgrade to Plat. Or, just ask for the 25K when you upgrade.