When someone makes a purchase using the credit card option, do they get a receipt?

Is the THANK YOU page the receipt after they purchase or should I create my own receipt and have it redirect.  I just don't want there to be any duplication.

The thank you page is not an actual receipt, but you can indeed use it as such - the thank you page is simply a page that your users are shown after a submission or a payment has been made. You can also set up an email autoresponder that will send an email to your users upon a successful submission/payment.

For practical reasons, it may be prudent to set up both an autoresponder email and a thank you page containing the users payment details. The thank you page is shown to the user immediately upon payment/submission, and the autoresponder email is sent to their email address so that they have this information saved for their own records.

I hope this helps.