No Response on Faulty Cellphone

I bought a Sony Z3 Compact 7 months ago and initially the phone was everything I hoped for and more. I have started up a small business and this phone could handle all my business requirements as I do eveything via my cellphone. About a week ago the phone suddenly just died, refused to start or charge. I read up on everything possible to do for this phone but to no avail. I sent Orange a message to their customer support telling about my problem and that I would like a replacement phone and not my money back as I do need the phone for my business. 2 days after my phone dying it suddenly came to life again and I was overwhelmed with relief. Guess what, it was short lived, two days later the phone died again and is still not going on. I have lost thousands in business and will now be consulting with a lawyer on suing Orange for loss of income as they still have not bothered to respond to my email. Im fed up. I need a new phone and not my money back. So even if customer service wants to call me now they cannot as I have no cellphone to answer but they didnt even bother to respond to my email. I will definately be suing for all the money I have lost due to this faulty product.