Hello, about 1.5 years ago I bought a new Soda Club CO2 cylinder in a Migros store for 48.50 CHF. At the time I was surprised at the high price, but it was explained to me that a rental fee was included, which would be refunded on return. It actually came with a certificate booklet stating that you get CHF 35 back when you return it. Now I want to return the cylinder. However, this is probably not possible in a Migros store. I could probably do it at the manufacturer. But the problem is: over the course of time, a Migros employee changed the cylinder from SodaClub to Migros Classic. I didn't even notice this (as long as the bottle fits). But now, of course, it's a problem when I return it. I only get CHF 10 back from Migros for the Migros Classic bottle. Of course, I don't have any proof that the bottle was replaced "by mistake" without asking. In general, most Migros employees are not very well trained when it comes to CO2 cylinders. Once a cashier gave me back an empty cylinder as an exchange, which I only noticed when I got home (I hadn't noticed it in the middle of my bulk purchase). However, she corrected this without hesitation when I returned to the store immediately afterwards. On another occasion, the deposit was not deducted. I hadn't checked this immediately (when buying in bulk), so I was out of luck. It's all worked out over time, most of the staff now know the product. But it's very annoying that I now have the wrong bottle so that I can get at least part of the high purchase price back.