Dollar General

Went into the Dollar General in Imboden Arkansas to purchase a gift card to give to a single mom who needed some help. I asked the manager how much the activation was since I had seen a sign up that they was one sale. She informed me that it should be 2.95 I purchased a 90.00 gift card went to leave the store noticed it was 4.95. After asking the manager who was not very nice she informed me sign was for a totally different card that was across the store. I asked her if they could refund the card to honor the sign and she said no. I was very upset because the signs was up, and it wasn't honored. She said there is no way to fix this issue after purchase, and admitted that the sign was for a different card.