Amul / Gcmmf — Amul Masti dahi stale and bad taste

Bought amul masti dahi from nearby local shop.The taste of dahi was very bad there was some kind of foul smell when packet was opened.The taste of curd was very bad and disgusting it was like some kind of powder was mixed with curd.I thought that i had bought expired product but when i checked the date i saw that dahi was within its expiry date.
Don't know how they are preparing it's curd never expected this from amul.From now onwards will try other brands of curd.