Need help with Apple and gift cards

The first question is I have gotten a few charges through the Apple store that weren’t approved. This February I was charged two different charges but that whole week my family and I were on a cruise and had no internet access (we had our phones in a safe turned off) so I have no idea how I was charged. Also my daughter can’t purchase anything on our phones with me approving it first on my phone with my fingerprint. Also a few days ago my daughter asked to purchase something on her phone Which I approved it but it never went through on her phone so she couldn’t get it. Well today I noticed Apple still charged me.

And the main reason I’m contacting Apple is my daughter saved up her money twice and bought two App Store/iTunes gift cards and we loaded them on her phone but it won’t let her use them on her game. My husband and I have tried everything. It shows the money on her phone from the gift cards but when you click on it to use the money it asks for the code on the card again. We put it in for both cards a second time and it’s saying that the code was already used (which they were because we had to use it when loading it to the phone).

we are beyond frustrated. Please help!