ISPs cost me a fortune in patch leads too. I "lose" approx 10 a month.
There's an ISP in London based near Vauxhall that has a nasty habit of shifting blame to third party techies...won't name them...but we used to call them Skip Fire, Tyre Fire, Time Liar, Spit Bucket, Phlegm Hire...whatever vaguely rhymed or involved sputum.
"Ok, I've got a Skip Fire job to put out today"
"Oh man, Spit Bucket want to do an installation at 5:30 pm, today we'd best make sure we have an engineer there for when they arrive tomorrow afternoon".
Haven't dealt with them for nearly a decade but I used to have to deal with them regularly and their installations were regularly shit, late, botched etc. Usually something to do with the garbage Zyxel routers they used for DSL, they would either fail entirely or arrive with no configuration done other than them changing the admin password (which used to be the same on ALL the devices they shipped).
Didn't take long to figure it out for most of us, it was the company name as the username and the same for the password.
We'd regularly get the blame for their ineptitude.