Xiaomi India — Faulty Battery from Xiaomi Service Center

I purchased a brand new battery for poco F1 phone from a service center in vanasthalipuram Hyderabad for Rs.3960 /-on March 28th.. The battery they replaced was faulty. I sent them the daily report of the battery backup which is not coming even for 3 hours. For 3 days I took screenshot and shared it across to them. After that I visited the service center and asked them about the battery. They told they will order a new battery from Bangalore head office and will replace the same with a new one.. They told they will notify me once they get the new battery. I waited for their call for 2 weeks and today I visited their office again. Now they started giving me some lame excuses and replies saying that they need to format the phone then only the battery issue will get resolved and will work perfectly ... Before that their version was different and now they completed changed thier version. Is this the way the service center of Xiaomi works.?