Faulty Equipment followed by ******ion

Rocket Party Hire delivered electronic equipment (for an outdoor cinema event) that did not work. The equipment was rigged up onto scaffolding but no technician was supp**** to operate the equipment and no calls for support were answered. The event was obviously a disaster. Now we are being threatened in emails, demanding money by this hire company, saying that we have to pay for the replacement the equipment, which firstly didn't work and was then left in the rain because they were too lazy to come and derig and collect before it rained. We were also charged for the derig and collection. I contacted them at 7am on the Monday morning asking them to collect before the rain. They showed up over 5 hours later and now telling me that I should have derigged and put their faulty equipment under cover! Shameful and *********.