Welcome to the forum. No freebies - you have to pay it all off. When leaving CH ( deregistration - you can search the forum on this word for more answers and shared experience ), you can send the deregistration paper to the phone company. They may allow you to "break the contract" by paying a lesser amount than you otherwise are contractually and legally to pay.
When searched, you will threads like this:
Orange iPhone contracts: that pesky termination fee Mobile Phone Contract... Mobile Phone Contracts had any problems Can I cancel an Orange contract? Mobile phone cancellation - englishforum to the rescue!