I remember that a couple of years ago if you officially left Switzerland your mobile contract could be automatically cat off and you didn't have to pay anything (which I actually find unfair for the companies).
I asked at an Orange store here in Lausanne if this is still the case and the guy told me there's a new process and you can't cancel your contract for free any more. But he couldn't explain me the details, because it's a new process and it's managed by the customer care.
Does anybody know what exactly you have to pay?
In my opinion, it is fair to pay the pro-rata amount of the subsidy you received. For instance, if you paid 200 francs for a phone that at the time costed 350, are on a yearly contract, and you cancel it after 7 months, you should pay 5/12 of the 150 francs of the phone subsidy.
Or, if you got a contract without a phone with a discount on the monthly fee, you should pay 5/12 of the total discount.
I really hope they didn't introduce some crazy ETFs (early termination fees)....