What have I back peddled on?
If you don't want to attend a non contract customer, thats understandable, and just say so to the customers face.
I do it all the time, less often when it's known timewasters where we put the original kit in, but even then I do say 'not today'.
Just don't go promising immediate attendance and then not turning up - as it sounds here for the OP.
That was my point then and my point now.