Bummer this happened and like others glad yoiu are ok. Lot of gutts to make that jump. In the heat of the battle little things like drag the hoe or drop the bucket don't always hit the brain pan.
But I would have called them and left a message the moment it happened. That and on tractors and such the hour meter would be the tell-tale on how much you used it and what you should pay. Around here a daily rental is actually 8 hours on the meter, not 24 hours on the meter. Sorry I'm one of those you saw what you were renting, they delivered, and you used some, sort of like the plumber you call out and he says your dishwasher is wasted, you still own him for the call even though you will buy and install one from the local HD.
But we've all used or heard the term "it's a rental!!". And people beat that stuff to no end. If you are lucky you get or wait for a new piece of equiptment. If not you take what's there. Like dfkrug mentioned, sometimes it's cheaper to rent the old stuff. If this was $200 a day would you have paid $400 a day for a new
L35? Probably not me because I'm cheap.
If was me I'd just say I'm glad to be ok, never rent from them, if I only used it for 4 hours then try and get half my money back, and move on. Because someone else is going to rent that POS, and use it all week without any problems.