Rusted pin in my food

I bought fish there and when I broke the fish up for my 3 year I found a rusted pin in it.when I phoned to complain they told me that it is really bad and even sent them a picture of the pin and the proof of purchase.he wanted to give me a piece of fish free.my chid could of been died if she has swallowed the pin.i will never buy there again and this is the first time in a long time that I bought there.