Apple Gift Cards

I recently purchased a Apple gift card for a christmas gift for a family member. I purchased the card at my local Walgreens. I picked the Apple card that said $10-$500 on the top of the card thinking I could put $300 on the card. I proceeded to the checkout and I told the lady I wanted to put $300 on the card. She then swiped the card collected my $300 and gave me the receipt and I left the store. At this point I thought everything was good. A week later, I give the gift to the family member and he was excited and while I was visiting with other family he went about his business with the card but a few minutes later he returned and asked me if I said there as $300 on the card or $50 on the card. I replied $300 he then showed me the card that he removed from the sleeve and the card was a $50 dollar gift card. It has been a nightmare resolving this with Apple. I contacted them and after about 3 hours of time on the phone over a 2 day period I received a text message with a new code. That is what the message stated, and gave me a number. What am I to do with this number??? This was a gift and I gave the family member the code sent to me and they now are having issues redeeming the money and told me the card was no good now... Can anyone see my frustration here??? How the heck do I resolve this because I'm getting no where with apple customer service.