Volvo Rents

We rented a backhoe in January and it went well.  We rented again in March. They sent us an older used smaller backhoe. It had a power issue. My husband was using it by our creek. It could not power to walk sideways, and set above a rock. The drive line broke or came out and was flipping around. It dented the oil pan and broke a hydrolyck line.
We called the company and they were very prompt in sending a newer one to replace the broken one. 
The delivery personell drug the broken one up our steep drive way. Left it parked on the incline. It started rolling back and the delivery personell ran and jumped in and set the brake 4 feet from a 12 foot drop into our creek. They then drug it some more. Sideways, foreward, etc. Could not get it out of the drive way.  They backed the low boy up and drug it up to the top of the road. That is were the employee then decided to start it and drive it the rest of the way out of the drive way.  It sounded fine engine wise. We discussed charges and they said the fuel and rent would be prorated to the running backhoe. They loaded it and left.
While they were delivering the one that broke: I am very thorough and asked the delivery person if it had insurance in event of damage by us or from any breakage not our fault. He showed me on my invoice where we paid for both types of insurance.
Josh from Volvo Rents calls my husband and tells him we owe $2131.81 in damages. I go in a few days later and inquire why. Remind him of what the employee says.  He tells me he was aware of what his employee said. Said he mis understood the insurance policy and tells me the insurance does not apply. Apologises and says he is aware of that. Insists we owe that. I let him know the customer (me) feels like I am getting the dull end of a knife. Customer should be right. He says he is sorry I was mis informed and I must pay. Again I tell him his employee said it is covered. He says no. Back and forth we go. I asked him to at least meet me half way on it. He said he did. I ask him who is doing the work. He said his new mechanics. I then asked for him to wave the labor charges since it is in house repairs. He says no.  He is not willing to budge.  I write the check. He gives me an itemized bill.
My husband goes over the bill and finds "Repaired driveline for the unit. ALSO replaced dameged oil pan with new gasket had to replace pinion and gear on front axle because it was sheared off when driveline was broke also front seal on yoke was changed out".  My husband feels excessive things were fixed and we are being charged for them.
I called my attorney. He said in the state of Az, verbal warranties with an oral modification of contract is modified it then replaces the original contract. Volvos' delivery employee did this when he told me it is covered under insurance. I was advised to not pay.
I went to the rental office on Friday, and requested my check back.  When I did they asked why and i told the acting supervisor why. He started to verbally batter me. Started escallating his voice and said they would then send me a bill for twice as much since they only billed me half. This was never told to me prior.  The man kept brow beating me. I finally said send it. I then left with my check in hand.  I will not rent from them ever again.