When I answered the phone, the patron asks,
Can you tell me the phone number for 1-800-Go-FedEx?
At first it sounds like a prank phone call, but this is actually a good example (ie, trick question) for a reference services class. This particular patron is blind, and so can't easily correlate the letters of "Go FedEx" to numbers on her phone's keypad.
I'm not an expert on accessible equipment, so maybe there are phones that do have the letters indicated too, but this seems like a perpetual problem for low-vision people.
Anyway, instead of manually figuring this out with our desk phone, which would have taken more time, I just did a quick search for "800-go-fedex" and found it listed on FedEx's Customer Support Phone Menu webpage as 1.800.463.3339.
And my call was the second time. Earlier that evening, my coworker had told me she got this call (and that it initially struck her as odd until she recognized the patron's voice) - but I guess the patron had forgotten the digits in the meantime.