Prestige Smart Kitchen — Non Stick Tava

Address:

Ajmer, Rajasthan, 305801

I purchased prestige non stick tava from authorized retail outlet in Kishangarh City. While purchasing the tava, i inquired everything about it and came to know that its metal spoon friendly, so i used it with metal spoon but soon i can see some mild scratches on the surface of the tava. i went to retail outlet in this regard, but instead of listening to me, the person there started saying that you dont know how to use tawa and you might have used scrubber or harsh chemical and all, and it is not covered in the warranty.
i dont know what to do? i have purchased all the products of prestige only, cooker, gas stove, non sticks, tava etc.
i have bill and the box with me, which clearly states that its metal spoon friendly.