I got this email today..

Greetings from IHG’s Best Price Guarantee Support Desk!

Please accept our apologies, but due to some technical difficulty, we were unable to adjust your reservation to reflect your free night on XX Oct 2012 at the XXXXXXXXXX (Holiday Inn Express Hotel & Suites).

In order to fulfill the Best Price Guarantee promise of providing the first night free for reservation number 6512xxxx, we will reimburse the amount you paid via check which you can expect to receive in 4 - 6 weeks after your hotel stay. Please provide us your complete mailing address where you would like your check to be sent. Again, please accept our apologies for any inconvenience that this may cause you.
Thank you.

If you need further assistance, please feel free to contact us