1-800-478-8053
http://www.customercarehelplines.com/yahoo-customer-care-helpline.html
Found spammed here
Only one guy working there at the moment in Surat, Gujarat. Still working on further details but hard when its just one guy as verification is not possible.
Edit: I take that back, there are a couple of them (I just happened to get the same guy six times) LOL.
Spam calling them with soundboard, they now answer the phone without speaking, just silence 
At least their “customers” or more properly victims won’t be able to get scammed while they don’t speak.