How do I redeem my voucher?

Hey guys and I wanted to get a voucher in a bookstore for 3 months ps4 plus. But I only got a voucher from the voucher and not the card. Now I do not know where the code should be. Have already entered all possible numbers of the document but nothing works. Can someone help me?

Maybe there's something on the coupon? Do you have to scratch something?

I've never got the card but only a receipt

Normally the code should be on it. If that is really downhere on it you can definitely determine where you have bought, refund.