ESP Air Conditioning & Heating Service

I was hired to install a used unit that the coustomer and agreed that there would be no warrantyI installed the a/c unit that did not even charge her for only labor The unit ran for a week and a halfThey called me to come look at unit but was very rude to me on the phonei told them to get
someone else but they continued to harass me on the phone and email.I feel that I did what we agreed on and the unit was running when I leftagain I did not want to put in a used unit but they where persistent and we both agreed there would be no warranty.I feel I have done nothing wrong I did what we had agreed on the unit was working when I left