I accidentally created RDS and Redis resources other than Free tier, can I be exempted?

I would suggest to raise Support ticket towards AWS Support, they may provide some help on it . You can raise support case by going to Support section in AWS Console.

The first thing Support will ask you to do is to terminate the resources causing the unwanted charges. You can use your bill to locate which services you've run in which regions that month, to help you locate and stop the charges. Via your Billing Dashboard, navigate to your April bill to see what's been charged for so far:

https://us-east-1.console.aws.amazon.com/billing/home?region=us-east-1#/bills

Once there, take note of not only the services running, but the regions in which they're running. You may have to click the service name to expand to show the regions, or click "Expand All" in the top right.

If you want one on one help with locating and stopping the source of the charges, you can reach our Support team via a Basic Support case below. There are email, phone, or chat options - I recommend a phone call for the quickest assistance:

go.aws/support-center

— Chrissy B.