Depends on where you are, but in the UK you can't just hand the car back as you have a hire purchase agreement over an x number of months. In essence its yoru own problem.
What you can do is speak with the finance people who will look at your income/expenditure and MAY reduce your payment by spreading out over a longer repayment period. The only problem with this is that your agreement will start from scratch again and you will paying back a lot more. If you can really stretch and pay for it then try and pay it for as long as you can. Do, let the company know though as if there are any legal issues, you will be able to say that you contacted the company x number of times.
Most hire purchase companies don't actually care, I used to work for one and left in disgust because I didn't agree with how they operated.
Really wish you all the best.
Oh if you're in the UK, you can always contact the Citizen's advice beaureau!