I have had this problem too. Here is how I solved it, accidentally.
If you open your google adsense account and go to the My Account link.
Look at the Payee Information. The telephone number on record is there.
If the number there is wrong -you can change it or just enter the number that is already on record when you want to link to your account.
If there is no number showing you can try the edit link to add a number.
Payee Information  [edit payee name]
That should work. It worked for me and several others I know with adsense accounts.