Thanks to everyone who posted the idea of writing to plat team
I registered in April
Heres the reply I got from Amex today:
Good morning ,
Thank you for your email regarding the "Platinum Card - Get 100,000 Membership Rewards First Bonus After $1,000 Spend" promotion.
Great news! I have issued the 50,000 bonus points to your account for the better offer you received. Currently, you have XXXXXX points available in your account.
?? , thank you for choosing American Express and we look forward to serving you for many years to come!
Sincerely, Bianca Perez Email Servicing Team American Express Interactive Services