Dealers not wanting to do warranty work.

I have a Handyman Service in our area. It is a one man operation that fills a void in our small community. I do RV repairs when called among all the other stuff I do. There is no RV dealer of any kind in our area, the closest is over an hour away, if you know the roads. We are on the west side of Table Rock Lake, a vacation destination for RVs as well as weekenders. I was called upon by a weekender that has his Forrest River product setting on a site here. They had a skylight leaking. It was cracked, the unit was 2 months out of warranty. The selling dealer is out of business, they had no one to turn to. I suggested they call the manufacture, and see if they could help or at least let us know how to get a new skylight. Forrest River stepped up and said they would not only send us the parts at no cost they would pay the labor for them. We all thought that was fantastic. I got all the info to send them the bill. I promptly sent Forrest River an invoice for the labor by email, and received a confirmation. 4 weeks had gone by, no check. I sent a reminder, Forrest River replied "Our payment terms for checks are NET 60 from the date of receipt of invoice which would put you at about 1/14/14. Or by ACH we pay NET 30, if you would like the payment sooner via ACH I’ve attached the necessary form. The work was completed on 10/31/13, I could send them all my bank account information if I wanted to get it sooner. I will be damned if I am going to send any one my bank account information. It is no wonder no one wants to work on anything the factories have to pay for. If I had to by parts and provide labor to them interest free for 60 days, I don't want to do the work either!!