Faced similar problem
Conveyed to yahoo, had this response
"On the change form, we ask for the email address you originally used to submit your request. If you can't remember it, use the form anyway, including any possible addresses in the "Message" area. This will help us locate your record."
A few weeks ago. I know they say to wait 3-4 weeks, so I wasn't particularly impatient. Not having had success in about 3 weeks, I'm guessing it's because the e-mail address(s) that I'm using for guessing aren't right. So I filled out a few of their "trouble tickets" asking for further guidance, without any more success.
Now, I did notice this time an e-mail address for url-support. I might try that also
-- This message may have been cut off and the rest will only be shown to members. To become a member, click here --