Since they were PIN based, your processor is correct, you cannot file chargebacks. You can try to work directly with the merchants...some may require that the request come from law enforcement so you may need to contact the local PD for help.
As for your customer, since the card was stolen, and ATM withdrawals are not covered by Zero Liability, their liability would be based on Reg E 1005.6 and how soon after they discovered the card missing that they notified the institution.
The obvious question for your customer as part of your investigation is, "How did the thief know your PIN?"
Could have been written on the card, shoulder surfed, phished, etc. If you consider this customer a risk, you may choose not to reissue a card to them.
Last edited by BrianC; 05/09/13 09:47 PM.