Iphone 5 screen bugging out?

Recently, i dropped my iphone 5 at a hockey game and the screen broke very badly, and it started building moisture, so i took it in to a local iphone repair shop. The guy replaced my screen for 150 dollars. When i got home, i realized the the E button wasn't responding, and rw was being typed instead. I disregarded it. Later the next day, i noticed icons being touched on their own. I restarted it and it happened 5 minutes later. Its been 5 days and its unbearable. Its touching random buttons every second, and i can't use my phone because of this. I don't live near an apple store. Is it possibly a cheap screen? Did the guy not connect something? All of my software is up to date and my phone is not jailbroken. The bugging out is absolutely crazy and i can't deal with it. I have my old working iphone 4. I can't upgrade since i anm on a plan.desperately need help as my phone is unusable.

Take it back to the store which repaired it and tell them about this.
Make sure you take your invoices.
If its not working properly after the repair, it's their fault.