Most likely a postage service has been selected at some point - to figure out where the error is, the best thing to do is go in and revise the listing and check the postage section.
You may need to click 'Add or remove options', so that you can select the 'No postage, local pick-up only' option, which should remove the postage service/quote options.
You might also want to change the Cash on delivery option to Pay on pick up in the payments section, as cash on delivery generally refers to having the item delivered to the buyer and they pay the deliverer when they receive it.
