John is right on the mark. Basically, if you can't prove your customer did it, authorized it or received benefit, the claim will need to be paid.
Depending on how good a "friend" it is, emphasize your intentions (assuming it is so) to file a PD complaint and to prosecute to the fullest extent possible.
I'd also hold the customer's $50 liability back and cancel her use of a card since she was not careful with it in the first place.
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AndyZ CRCM
My opinions are not necessarily my employers.
R+R-R=R+R
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell