Hi everyone,
I just wrote a guide for those who have bought an Oneplus One in Switzerland.
The guide was posted on the official forum of Oneplus:
https://forums.oneplus.net/threads/guide-enable-lte-with-swisscom-switzerland.97469/
Hope it will help!
I opened a ticket 3 days ago and solved it yesterday, maybe this would help others Oneplus One buyers 😛