cool now

Cool now rep. came here to clean my a/c unit. infirmed me that my a/c unit was not working properly and talked me into buying a new a/c unit which I did not need. I informed the rep. at this time that I have health issues and take meds. I should not make decisions. he was very percistant and convinced me that I needed a new unit installed. My daughter and grandson had just left for work. I do not have a job and live off my Social Security. Please help me, I dont know what to do!!