Redeem code not working

So earlier when I used to redeem a code it used to work,but now all of a sudden none of the codes are working for my account.i have double checked the code, the site and my account, everything is correct but it shows invalid.My friend redeemed the same code in front of me and it worked for him but not for me.My ea account is also connected and everything else looks fine.Also,I have tried various codes.None of them is working.Please help