A customer is alleging that they did not authorize several electronic transactions. However, we think that she did authorize them and want to ask her questions. She will not return any of our repeated phone calls. Is there any way that we can say she didn't cooperate with our investigation and not give her credit?

Reg E 1005.11 is clear on what the customer's obligations are when making a Reg E claim. The customer must provide you with enough information to identify their name and account number, and why they believe that an error exists. The obligation to investigate is on you. Once your customer has satisfied the notification requirements, you can not require anything additional from them.

I agree with Brian, but also recognize that if this person wanted their money, they'd call you back.

I recommend you get the details you can. Ensure you call/write to the customer at the correct number/address. Document what you want, ask it in a certified letter, make the calls, and make your determination within the 10/45 day requirements based on what you have. If the consumer doesn't respond, technically that isn't required, but it did influence my decision. If you deny it based on what you do have, clearly offer to reopen the claim even though you don't have to, if they have more info.

I have found that this is one reg that people take advantage of.

This customer initially said 3 things happened all in a short period of time. She lost her debit card 2 weeks ago. She may have input her debit card info on a questionable website, and she lost her account and routing number information out of her purse. In the initial questioning, she said numerous transactions were unauthorized. The bank employee who questioned her noticed that some of the transactions were repeats of previous account activity. After observing that, the customer recanted that those transactions were unauthorized. Then, after the customer left, we noticed several of the other allegedly unauthorized transactions were similar to past activity. We have tried to repeatedly call her after noticing this, and she hasn't answered her phone or returned voicemails.

You are entitled to base your investigation on the totality of information available to you, including past transaction history, proximity of the places where transaction took place to the customer's home, work or the route between them, etc. YOu can also use evidence from other sources, like a surveillance camera recording at an ATM or a place of business. If, based on what you've seen, you believe the customer authorized the transactions, you can deny the claim and tell the customer he/she is entitled to see the documentation you used to arrive at your conclusion. If the customer is not responding to your attempts to clarify why she says a transaction wasn't hers when it matches similar previous transactions that she's not challenging, she's missing a chance to influence your decision in her favor. That's on her.