Hairdresser has burned my hair with bleach what should i do?

Two months ago I went to the hairdressers to get my v.long, thick dark hair highlighted. The week before my appointment I went to see them so they could see my hair before hand and decide the best way to do it. I told them that I had previously coloured it myself but not for approx 4 months. They had I look and a feel of my hair and said as it was so dark I probably wouldn't get the colour I wanted straight away and they would gradually lighten it(over a few months) So I went a head the week after. When I got there she got a cap out, I was unsure as I thought this was the old way of doing it, but she assured me it would be quicker and easier. So she started applying the bleach in a really mishmash random way and then i went to wait after thumbing though a magazine I had to tell her it was getting really hot, and she came and felt my head then disappeared and i heard her saying to another stylists 'its burning' They then took me though to the back where they rinsed it off. I could tell from the silence that it wasn't good. I couldn't see my hair for the cap but had at least three people were feeling my hair.(in silence). They lifted the front of the cap and said theat my hair wasn't taking well! What an understatement. I couldn't believe what I was seeing was my own hair. My roots were white, the lenghts were orange and the ends were still brown and there were orange and brown patches all over. Worst was the candy floss look I could see straight away my hair was burn to a crisp. Then they asked me what I wanted to do! I just started to cry and phone my mum(who used to be a hairdresser) she came straight down and asked them where the strand test was. They hadn't done one. as they tried to comb my hair it was just snapping off then they suggested covering it with lightblode toner til mum pointed out light blonde wasn't going to cover the brown bits so after she told them what colour would cover it thats what they did. So after what ended up being 5 1/2 hours of hell I had med brown highlights in shoulder length hair. and then they said that will be �38 please! So two months on the hair on my crown is just fuzz had to have more cut out today. and everyday more hair snaps off. I have had to put red toner on as their brown has now wash though to orange. I've spend a fortune in conditioners frizz ease hotoils and other treatments. Can someone please give me some really advise on how to deal with this salon. My hair is ruined and will take years to grow out. Everyday my hair gets worse. Please help