I live/work in an area which is near the border with a neighbouring country and I often get high bills with calls made in roaming even if I did not leave Switzerland, what is happening?
Your handset has probably switched automatically on a roaming network. You should block the automatic change of operator in your handset settings. To be sure that you are still using the network of your swiss operator, you can simply check the indication on your handset screen, most of the devices let you know what network you are currently using. In order to avoid that your handset switches on a roaming network automatically, which would result in higher bills, it is advised to block the automatic change of network in your handset settings. If you need help to set up your phone, you can get help from Orange.