Nutraj - expired walnut recived with before expire date

I ordered walnut Through swiggy instamart After receiving my package I was opened next day morning Open my walnut pack and i eat that i had an allergic reaction after eating walnut like headache ,voimiting ,vertigo .I immediately checked that walnut bag after the expiration date There was still plenty of time left in that walnut to expire The walnut smelled like the oil was wasted When I contacted the company about purchasing the item from a non-existent place called Swiggy, they did not give me an proper answer