i got a 3DS points card for christmas, but when i go to put in the number, it said " the number cannot be recognised, please reenter agian" i did reenter it again but it showed the same error. does nyone know how to fix this?

You probably should contact Nintendo as they will be the only ones to fix this problem.

This happened to me once and I called Nintendo. I gave them information from the card and they were able to find that it was indeed purchased and they credited my eShop account almost immediately. Only took about 20 minutes total.