We have a customer that gives her Debit card informatin to her Daught & Granddaughter to use for onr purchase and they used it for more. The customer called and would like to dispute the charges as not authorized. What steps should have been taken?

The daughter and granddaughter should be bent over a knee and severely whacked a few times.

Seriously, you open the investigation and either deny or agree with the claim. You might mention that if you pay the claim, you will pursue the daughter and granddaughter criminally, if possible.