I have literally never had anyone refuse to help put my tarps up on the load or even the trailer after unloading me. Most, in fact, offer to do it before I even ask.
I don't have your luck, I've had many places say 'company policy' or 'insurance' or 'the law' doesn't allow them to put my tarps up. I say no problem, my 'company policy' doesn't allow me to climb a ladder and carry them up there either, so it won't get tarped. Best of all is the places that load you 13' high and expect you to carry a tarp up there, and also you can't tarp on their property you have to leave and do it somewhere else. Not going to happen, OSHA requires the shipper and/or receiver to provide fall protection for tarping. Too many drivers with the macho 'git er done' attitude have fallen and gotten severely injured because some ignorant customer or carrier insists this is what must be done. The only person that can truly watch out for a driver's safety is that driver himself.
That's actually how I got my new ladder. I had loaded in town, and brought it home to tarp. I was talking to the wife as I was carrying the tarp up my 6' ladder when I noticed it was only rated to 225 pounds. Me fully dressed is pushing it...and there I was carrying an 80 pound tarp too. When I found the 8' ladder with a 375 pound rating a few weeks later, there was no need for discussion...no "you already have a ladder"...no trying to explain or justify the purchase. She was actually HAPPY that I spent the money.
If I could've run it same day, wouldn't have had to tarp...but sitting on it for the weekend with a possibility of rain, it had to be covered. That & why tarp it at the shipper (alone) as it was quitting time and they were all going home, having to climb all over the trailer and load (no ladder), and I was just about out of ice cold sweet tea (like I said, end of the day), when I could go home and do it there, where I could visit with the wife, use the ladder, and had a fridge full of ice cold beverages to choose from?
Rockingham canvas company in Harrisonburg VA. Just had some custom made there with 14oz vinyl. Super light but a handful in windy conditions. Paid $475 for 2 tarps one 24ft one 22ft.