IMO, you'll create a whole bunch of headache for yourself if you take the rig and then cancel payment. Most likely you'll lose the credit card dispute and if you cancel the check as noted, that's considered fraud in all States...I know there's tons of case law about that in California. Best spend a few $$ with an hours' attorney time before doing something foolish over a paint job.
Ok...here's hoping the redo is perfect! Have you called Monaco and had them email you the paint code sheet for YOUR vehicle? They have them or it should be in your factory book if you have it. It's always easier for the painter when those are provided. If the job is not to your satisfaction, you'll have several choices...take it "as is", negotiate a better price and take it 'as is', or have them redo it a third time. Keep in mind I doubt they will do it a fourth time...good luck..keep us posted.....Dennis