Amul Dairy — amul milk

Respected sir,
I have purchased 500 ml amul milk today i. E 12 sept and the date mentioned at back is - use by 13th september, 2019. After 5 min, i started boiling the milk but the milk ejaculated. It contained another layer n started smelling.
This was happened before also but i thought i may be due to summers and ignored. But day by day the brand value of the amul is getting decreased. I was the loyal customer of amul but due to these incidents the trust is getting broken. This is not done. The products of amul are getting deteriorated before the expiry date. I would request you to look into the issue and do the needful.