Hire-it gives you inferior equipment & don't deliver on promises

So, a few week ago I hired a couple generators from them. I specifically asked for diesel generators. Not only did I get petrol generators, but I had endless problem with it. Of the 4 which I hired and the 2 which they gave as backup, I eventually could only use 1 because the other generators refused to start. Yet stupid me decide to hire 5 site fences from them. On Friday morning, I go and pay for it as well as delivery and collection. I also make it clear that I need it to be collected first thing Monday morning because it is an open site and there will not be anyone after 10am. Monday morning, I arrive at the site to ensure all deliveries are collected, the toilets, bins, ******* etc. At 11:22 I make my first call to Hire-it to make sure they collect. They say the driver will be there shortly. At 11:42 I can again and the driver is still on his way. I tell them I am leaving the site and I return at 12:40. At 12:43 I once again call and get told the driver will be there shortly. At 13:23 I call again and get told the driver will be there shortly. At 13:53 the driver pitches and explain the real driver will be here shortly. I then get a call from Mark and Grant saying some of the fence feet are missing to which I respond that it was there when I left the morning and I was promised collection in the morning. Hire-it are not the only ppl needing to run a business, yet their expectation is that we lust look after their stuff to they are available to collect, even though they agreed to collect it first thing Monday morning. Now they claim I am liable for their loss of feet when they did not collect when agreed to.