I had a few like this not massive jobs, £20 - £30
Alot easier cleaning than getting paid.
It got to the point where I was going to dump them.
I left a letter to customers concerned saying that from next clean it was standing order only.
I said that everyone on my round was being converted to standing order (not true just these few pain in the bum customers).
I said that prices would be fixed for 2 yrs.
4 customers concerned excepted.
1 of the customer's played the waiting game and contacted me 3 months later asking why I hadn't been.
They denied getting the letter, even though I had hand posted it through their letterbox in my envelope's I'd always leave with a bill card. 😁
I joked it had probably been scooped up with the junk mail.
They set up standing order too.
I would refund these customers if I was late but always make sure these are done every month.