I just got screwed

I've been using a credit card for awhile (I dont run a balance so I am not getting charged) that has points for use for anything for your car (minus Labor costs.) I have earned $425 in rewards. I was going to use them to pay for a grill guard fro my truck. Turns out that is not allowed, but you can use it for a down payment... So I said ok, Ill use it for that... Nope cant do that either you have 90 days from the date of purchase (which is written NOWHERE except on the form to redeem them, I have now gone back an re-read the terms to figure out where I went wrong)... That expired 6 days ago... So basically I'm screwed. My bad...

I can also use it for maintenance and repairs (but only for parts not for labor) and guess what! I have a full warranty for 6 years!! So I won't be doing that anytime soon!!!

I should have known... Too good to be true. The only reasons credit card companies exist is the screw the consumer, and they just got me.