From healthy hair to burned elastics in less than5

I bought the mediscalp hair straightner kit and started doing what it said. Not even 5 minutes in the procedure, I saw in the mirror my hair was going brownish red. I immediately got into the shower and washed it off. My hair is so damaged, it's like pulling elastics!!! From healthy hair to this in minutes. I went to a salon and the lady said the only way to fix this is by cutting my hair short and to wait for it to grow back!!!!!! This is unexceptable. How can you have this with false advertising saying it's not damaging???? How long till my hair will be back to normal? I am walking with a towel w***** around my head because that's how bad it looks!!! Do I now have to stay indoors till it grows back?????!!!!!