Call and use code ZGAA, that should get you 5000 miles after signing on then 1000 miles/month for next five months for a total of 10K.
I called and asked about the 25K offer three times and gave up, all they would offer was 5K given 1K month. After I refused the last offer of 5K and hung up my phone, they called me back and offered the 10K. The code they gave me was given to another rep at a different 800 number after I signed on. When I called the second rep with the code, she knew exactly what it was for and repeated the 10K offer. LOL