I opted for "OLAY" products, which required me to spend a minimum of $100 for 49,000+ free credits.
In what manner did you make your purchase? By following the links through the app or going to the Oil of Olay site directly?
If you accessed the site through the mobile app, after purchasing, by going back, by using the "back" key, to your opening screen, the credits should have been awarded right away. I did the same thing, but I used a VEMNO card (used as a credit card) and my credits were awarded immediately.
WGT was zero help and referred me to something called "tapjoy"
"Tapjoy" has been of no help
Tapjoy runs the promotions, but WGT process the credits. I would stick with emails to email@example.com. If you can, attach a copy of your proof of purchase, showing date and amount. Let them know that tapjoy is ignoring you. With enough pressure, you will get your credits. You may want to mention that you will send an email to Oil of Olay customer service to advise them of the situation.
It is also possible, there is a delay in awarding credits when payment is made through PayPal, I would not know having never used PayPal for any online purchases other than Ebay years ago.