Gameboy Color fix and case change

Hey guys, any recommendations to send my Gameboy Color to in the UK for fixing and installing an OLED modded case?

I tried to change the case and screen out for my working GBC and I must have shorted it or something as now it doesn't work. I don't have the knowledge to figure it out so wondered if there was somewhere I could send it for repair and where they would install the new shell. Any suggestions would be greatly appreciated!