The developer is a thief!

I installed the plugin, I liked it. I got in touch with the developer “Narayan Prusty” to help him improve the plugin. he instead told me there is a premium plugin available to buy at $19. I told him what I need and he ensured me he will support me through it and if the plugin stops working, he will update it to fit to my needs. Now I bought the plugin, it has huge flaws and bugs and he won’t return my mails at all. Please DO NOY BUY anything from this developer or you’ll end up where I am right now.