Phone Battery Draining

I have purchased a phone from amazon on 28/01/2016

After 20-25 days i came to know that it’s battery is draining too much.

Then i made a call to Mi Customer care on 1/3/2016.

There they suggested me to visit Mi service center.

Then i visited service center & given phone for repair.

After 15 days i noticed same problem again.

Then again i have given phone for repair on 4th April for same problem battery draining.

Then i have given phone for repair third time on 7th April

After repair i got same problem again.

Then i have given phone for repair 4th time on 15th April.

Then they told that it’s the last time that i have visited MI service center.

Because they are changing battery.

After battery change i got same problem again.

Problem is same again.

It’s almost 75-80 days that i have purchased phone.

And i have given phone for repair four time.

Still my phone is draining battery too much.

Still i got no solution for the same.

I don’t expect such a cheap service from any reputed brand.

Please intervene.

Regards
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