I "never" text beforehand. But being a softy over the years I I have relented on one or two if they have exceptional reasons. It always ends up badly.
The last one was last year when an 80 year old chap who was a bit slow on his feet and asked me to phone him - so he could put the dog in if it was out in the back garden and unbolt the gate (which I could reach over to unbolt anyway). I set out my store of no on the day cancellations and he agreed.
Got to the third clean and out he comes with a "can you leave it this time?" (with no good reason) which led to me informing him it would be a permanent cancellation to which he said "well that's it then old son" and concluded the call.*
I have too much work on with people that I agree terms with and who keep to them to worry about the idiosyncratic, the eccentric, the idiotic and the thoughtless.
*It didn't stop him asking me earlier this week asking me to resume.