The only rewards/club card I have is Spar. The points go on easily enough, but I had a big deal of trying to load it onto my phone for registration, as it had all kinds of countries to register with but not England! I tried the nearest one, Ireland, but that wouldn't accept my postcode being a different place, so in the end I had to call the manager out of her office, and she sorted it.
Then, when I went to redeem some points, the system wouldn't let me get into my account on my phone, stating it's the wrong username/password/email even though they're the ones I registered with! I went back to the manager, apologising and asking her to sort it. I gave her my password, username and email, and she couldn't get in either after 3 tries! So now, I still pass my card over but just let the points build up, as it's impossible for me or the manager to get into the account!