I bought today 10€ Spotify gift card from Finland Tuusula R-Kioski. I try to buy Premium with this code, but it says that code is invalid. I'm sure that I typed it right, I know its case sensitive.
Please could you double chek the code, and try again a few times. If it still fails to work, you'll have to contact the payments team using the Support Form - make sure you include the card number and serial number when you contact them.