Straightened Hair With Frizzy Ends?

I had my hair chemically straightened (Matrix Opti Soft) by a salon. On my way home I accidentally spilt a tiny but of water on the ends of a small section. I wiped it off as soon as possible.

5 days later I washed my hair for the first time. I then had fried and curly ends, where I can only guess, I dropped the water. I put a treatment on, but it did not fix it.

So I went to a salon and had my hair cut all over to remove the dead ends, and cut out the above said frizz. It was all gone and no more frizz. Washed my hair again, and now it's back. Same section of hair! Help?

By Suzanne