voucher codes how do they work

ZZaffy it looks like you were doing right actions but the codes probably expired. Because a lot of websites for codes allow people to share the codes they found and not everybody copy all the T&C.

And yes, it's worth perusing. When you start doing it right (finding fresh codes) it won't take much time.

As an example, that's how I usually by rail card. When renewal time comes, I go to a couple of sites I usually use and search for code. In separate tab I google code for any other sites. I pick the best discount, most of the sites has indicators like up and down. Often the best is expired but I try it anyway. Because I know that railcard site won't lock me out, I could try as many codes as I have a patience to do. So after like half an hour I either have a code that is better than from my usual sites or I settle for 10% which is quite standard for railroad card. So now it's like half an hour. But my fist one - I was searching and repeating for mabe 3 hours...

Just a thought- some sites don't like 'copy and paste', always try typing the code in before giving up. Sometimes it works, sometimes it doesn't but its worth a try.