If you want to unmatch with someone, please follow the steps below.
1. Go to the 'Message' tab, select the chat room of the person you would like to unmatch with.
2. Tap the options icon at the top right corner of the screen.
3. Press 'Delete this match' and confirm.
After you tap on 'Delete This Match', that user will disappear from your match list, and that user won't be able to message you anymore; any past conversations will be deleted and inaccessible as well.
Please remember that unmatching with another user is an unrecoverable and permanent action.