i bought an itunse card in store when i want to load the card is not activated

Some help here:

If you can't redeem your App Store & iTunes Gift Card, Apple Music Gift Card, or content code - Apple Support

Card or code is inactive

If you see a message that your card is inactive, it might not have been properly activated. The best option is to go back to the retailer where you purchased it and try to resolve it with them.

If you need more help, contact us.

Take it back to the store where you bought it. They apparently didn't activate it properly.