Nope, no mistake. That's cap1. There's no recon on anything either. Your score doesn't matter because your file is too thin. If you want it to grow, use it heavily. If you are using it enough, you should be able to get an increase at the 6 month mark. Also, around the 3 or 4 month mark, try to upgrade the card to a Quicksilver so you're getting rewards.
The great part about Cap1 is you can ask for a CLI as often as you like and it's a SP each time. As it's likely been stated, Cap1 typically puts credit lines in the range you've been assigned on the credit steps program and Cap1 loves to see heavy usage AND large (greater than minimum) payments made each month or even the same and multiples each month. Other than the credit steps program, I wouldn't expect much in the way of CLI unless all the following have been satisfied:
1) Heavy usage and payments in the last 3-6 months (typically over half CL utilized and paid each month)
2) No derogatory/no new derogatory since account opening (with Cap1 or otherwise)
3) Sufficient DTI ratio
4) No or very few inquiries in the last 12 months (theirs included)
I hope this helps and good luck on establisihing your credit!
Grats on the approval, but there's no mistake sadly. The Platinum is an entry level card with typically low SLs. Even if your increased Discover limit had reported already, it wouldn't make a difference as far as what Cap One would've extended you.
Not all "starter" cards like this are "bucketed"
My card started off on the credit steps program and is now a World Elite MasterCard with an $11,200 credit line...not bragging, just trying to give hope to others.