You should always on your own get a quote on Flood Insurance before you make an offer. The prior owners flood rate may not apply to you and realtors and home owners are not in the business of finding reasons for you to not buy a home. That is your job as a buyer.
It is also common knowledge that purchasing in a flood zone could in fact mean one day... you could flood. We also cannot predict when storms will happen... clearly the weather man is off sometimes too.
I cannot however understand why you are mad, and whom you are mad at? Please explain