Requesting refund

I downloaded this app so that I could have an external display for my laptop when I was working from home. I installed the app and my Windows 10 Pro Dell laptop and my iPad mini 2 tablet. I can get it to work as a duplicate main screen but not as an additional external screen. Ive asked for support but so far I have not received any from this company. At this point I just want my money back.

cwalt2054 about iDisplay, v3.3.0