Sales Emporium — Misbehavior and misguidance by sales emporium sales guy

I purchased a ac from sales emporium Baguihati branch from sales representative Bindu (mobile : [protected]). During purchased she confirmed that ac will be dispatch and installed on the next day. Based on her confirmation I purchased the ac and its 3 days she is not sending any installer to install the ac . When I asked she told I should not sell the ac to you. It is her mistake that she sold the ac to me etc etc. Why she has misguided me then informing that the ac will be installed on the next day without any doubt? I will ask all my relatives not to purchase any electronic gadgets from that store anymore. And want to return my ac and get my money back. With such type of behavior of salesman, sales emporium is going to close soon. I am assuring this. Kindly take necessary action if possible.