Amul Dairy — Coagulated Milk after heating

Address: Kolkata, West Bengal

At evening of 11/6/15 I bought 2 Amul Taaza from a local amul registered vendor. The milk on heating became solid. Why all of sudden the milk got coagulated out of no reason. On Inquiring the vendor refused to talk about this matter and behaved very badly. The quality was not good. The date of expiry was on 12/06/15. Request a refund.