How do I canceal a custom order request i sent to a client

How do I canceal a custom order request i sent to a client

Hi,

I created a custom order to show my customer what he should do, but he ended up accepting the custom order and making me having a request to pay him for the service which I am supposed to do for him. I have tried looking for a way to delete or cancel the custom order I sent to him but there isn't any button whatsoever to do that. Should I just ignore the request prompting me to pay and hope it wont affect my rating or better still, let it just be canceled. Thanks.