Hello @Matthew528,
Do you mean that the guest cancelled the request within 24 hours and before you responded?
If so then I'd contact Airbnb support to discuss the issue.
If it's that you didn't respond within 24 hours so the request expired automatically then, yes, that will affect your response rate.
The article below describes how the response rate is calculated.
https://www.airbnb.ie/help/article/430
Type "contact airbnb" in the "Search the community" box on these forum pages where you posted your question. Scroll down a little in the list of suggestions that appears and click on the "Contact Airbnb: A Community Help Guide[UPDATED]" one. That lists phone numbers and ways to contact them via Twitter or Facebook.
Steve.