Columbia's Milyong Pasasalamat Promo

I was doing the groceries when I saw this contest in the candy aisle. The instructions are not so clear, but anyway I will still post it. If any of you readers has more information, please feel free to write in the comments section.

It says "Get a chance to win over Php 4.2 Million worth of cash prizes! A total of 775 winners." Sounds interesting.

Promo Period: Oct. 18, 2011 - March 15, 2012
Mechanics:
1. Buy 3 different participating brands of Columbia products.
2.Write at the back of the envelope the following:  Columbia's: Philippines' Choice
                                                                             Name
                                                                             Complete Address
                                                                             Telephone and Cellphone Nos.
                                                                             Signature
3. Drop in drop boxes available in stores nationwide.

See posters and flyers for more details.

Unfortunately I can't find posters and flyers.

My question is, what are the participating brands?
What are the the prizes and when are the draws?
I can't find any drop boxes, can I mail it instead?

I already sent an email to Columbia Food, let's see if I'll receive a reply. I'll update as soon as I get more information.