Does anyone have an email address I can use for HQ (rather not use the web form so I can make sure it gets seen) to recognize great service I received at a Hampton Inn?

Or ideas/suggestions on how to best do this?

Long story but the front desk folks at a Hampton Inn went above and beyond in helping me with something, allowed me to cancel my reservation without charge moments after I checked in, and were very helpful/kind.

Especially for a non-full-service property I was very impressed and want to make sure they are acknowledged for their work.