Car accident due to garage negligence

Hi

I took my car to a garage to have its breaks done, they did all 4, i was driving the car 2 days later and the wheel flew off the car, hit the roof of the bridge i was driving under and we crashed into the curb. I had witnesses that were outraged by what had happened and said that doesn;t just happen, if i was on the motorway i'd be dead. When the green flag man came he felt all the wheels and non of them had been put on right, they were all hand tight rather than by the machine thats supposed to do it.  I went to hospital as i am 4 months pregnant and was worried about the impact on my stomach as well as my back hurting. Luckily the baby is ok but i have a sprain in my back and whiplash in my back/shoulder.

The garage have said they will do the work to repair the car as it will need a new wing etc, i now don;t have a car for a week which is a real inconvenience  especially as i am pregnant, i'm off work as the pain is too bad to sit at my desk.

I can't believe the company could send a car out without checking it was done and safe, if i were to claim for this how much do you think i would get???

Thank you for your answers in advance

Melissa