hi steve
i tell them that i come on that day once a fortnight or monthly whatever it is, and i stick to it!
so they get used to the fact come rain or shine we will be there,like regular binmen.
as i say i have lost one customer sometimes people come out and say dont bother and i smile have a chat and say no probs see you next time, but it is a good system and i explain i got to work to pay the bills.