Xiaomi India — motherboard fraud

Dear sir/mam
I hereby inform that i have purchased redmi y1 with imei no.[protected]/53 on 21/12/2017. But after a few months my phone was not working properly. Then on 4/10/2018 i registered my complaint in mi service center, hisar. They said me that your device needs software update, but due to software update i even face my data loss. After surveying the product they told me that my device has a problem of motherboard and they said that collect this phone after 3-4 working days. Then i collected it on 10/10/2018. But later on when i login to my gmail account in redmi y1. I came to know that my account was login on redmi 5a not on redmi y1, but i ignored it. When i was setting lock screen password i came to know that there was no fingerprint option in settings. Then i read the specifications of redmi 5a and found that there was no fingerprint option in redmi 5a. It means that mt phone contains motherboard of redmi 5a not of redmi y1. You know very well that you had done a fraud with me. But even then i hope that you will take initiative against it. Otherwise i need to take a legal against it. Kindly reply me within 24-48 hrs.