Reg Z. "Billing Error Disputes" 1026.13

Anything outside the 60 day timeframe is not a billing error notice. You are not required to take any action, other than most likely a courtesy letter to the customer informing them of the requirement that any billing error must be submitted in that timeframe and that unfortunately, there is nothing the bank can do for them at this time for 2 year old transactions.

1026.13(b) Billing error notice. A billing error notice is a written notice from a consumer that:

(1) Is received by a creditor at the address disclosed under §1026.7(a)(9) or (b)(9), as applicable, no later than 60 days after the creditor transmitted the first periodic statement that reflects the alleged billing error;