I stopped dealing with the non-Dave/non-Steve a long time ago.
Frankly, after spending a week on my knees making a perfect flooring, I found it mostly insulting when they tried to shortchange me.
Once I even had to get their wife involved to get the balance off them.
And, there was a joker who asked me for receipts of material so he could pass them on to his accountant and claim for them on top of my receipt!
In the last few years of working full time I ended up asking half the money upfront and schedule the work for 6, 8 or even 12 weeks later as I was busy.
That filtered down all the pi$$ takers and only good customers agreed to that.