Update (23.07.18):
Unfortunately, SodaStream bottles cannot be used here. For cylinder exchange please contact: verkauf@coolag.ch


Original answer (05.01.18):
The cylinders can be exchanged at an authorised dealer:

https://www.sodastream.ch/store-loca...

A delivery date is currently not yet known. However, as soon as we receive a new date, this will be adjusted.