Firstly, double-check your account just in case they are there or try loading up the game to see if they appear.
No sign of them? Make sure you've checked the T&Cs of the offer as you'll only get the free spins if you've met all the requirements.
Still unsure? Try clearing your cache and cookies (see here for how to do this) and log back in.
If there's still no sign of them then get in touch with our customer experience team who will solve the mystery for you.