Whats wrong with Huggies Enjoy the Ride Rewards?

I'm a teen mom 15 years old and my son is 7 months, I am signed up for the Pamper Gifts to Grow even though I'm only 15 they let my sign up for it using my own Birth Date. I need all the help I can get so I tryed signing up for Huggies Enjoy the Ride Rewards but it said I was to yonge to sign on and that got me a little mad so, I go online to get bonus codes for Pampers Gift to Grow and saw a 16 year old mom asking for codes for Huggies Enjoy the Ride Rewards, so I though maby you need to be over 16 so I used my older sisters birth date and she is 16, but it still wouldn't let me. And then I though maby she used a fake birth date maby you need to be over 18, I remember taking to my mom about how I need to find more dipper website that give you points for buying to get free stuff and she said I could use her birth date if I need to so I did but then it said I was to old and my mom just started her 40. How old do you got to be cause I don't want to use a fake birth date but they got really good gifts so I want to sign up has this ever happened to anyone else or is anyone else signed up for it and can help me out here?