I'm sorry to hear that it's not working out. Unfortunately sales is fully handled by codecanyon.net and I believe they have a very strong no-refund policy with a very very rare exceptions.
I have already went over my support duties to help you with integrating the search bar over the default one. I'm of course willing to help you with the upper mentioned problems if you decide to use the plugin anyways.
If you seek the fastest and most versatile live search plugin, then it's probably swifttype. Although please note that their business pricing starts at over 200$ per month, but for that service I think it's worth it.Best,
If you like my products, don't forget to rate them on codecanyon :)