This Match contact form just requires your email address but you probably could just enter your new one to contact them about your issue.
https://www.match.com/help/ContactUs.aspx
This is what Match states in their FAQ about contacting them about sign in issues:
Still Not Working - Contact Us
It was worth a shot. If we haven't been able to resolve your situation with the information above, please contact us. To help us find your account, make sure to include in your message your full name, email address, username, and ZIP code, along with a description of what happens when you try to sign in, including any error messages.
I hope this helps.