Flying on Turkish Air & getting miles Credited to United

[Yosel]

Trying to get united mileage credit for flights on Turkish air, and this is their response this morning.  ( I did not give Turkish air my mileage plus number at time of travel) What to do??
Thanks

Dear Mrs. ....... 
Thanks for participating in the MileagePlus program!

I regret to report that your missing mileage request is not eligible for credit.  The purchased fare classes (W and U class) for your airline partner travel is not a valid fare class for MileagePlus earnings.   

For complete details regarding earnings with our current partners, please visit www.united.com/air and click on the partner’s name.   

Whenever possible, we try to accommodate our customers' requests and I'm sorry that we cannot do so in this instance. We value your business and look forward to serving you in the future.     

Regards, 

Christopher Suyam
MileagePlus® Service Center

[yochai]

I'll answer since nobody else volunteered to (on both threads):
Not all fare classes earn miles on all airlines, some fares don't earn miles at all. This has nothing to do with giving your mileage number before or after the flight. Use wheretocredit.com to find out where your fare class will give you the most miles.