Damaged Goods

I have recently bought two items on Groupon - one is the car booster that i love and the other item is a set of Mayerhouse pots. I loved this pots but when i used the standard pot i use for cooking rice....it was leaking. it is not just leaking water content inside the pot. There is a brown rusty substance coming out when i cook. this is very worrying as chemicals are coming out and i do not even know the impact it has on my food. I stopped using this pot as it is pointless. i would like to know what groupon does in instances like these as i feel i didnt get my money's worth. please help.