Xiaomi India — Motherboard replaced and imei erase

Address:	Rewa, Madhya Pradesh, 486001
Website:	Mi service center

I have send my phon to red mi service center on service charge. They call after some time and say about problem in bettry and after that again call and say as per discussion we have replaced mother bord on chaeges of rs 3000 r but they don't gave any instructions about that.
After I have visit on center and ask me about phone he say to changes about 3000 after that i have told I don't need to spent much on these he changed all subject. Please help me
They already change my mother board old one and also eras imi no.