Vreni Schneider Ski School - Terrible Experience, Should I Contact a Lawyer?

We had a very disappointing experience with the Vreni Schneider ski school during the school break and I'm looking for advice. We signed up our 6-year-old son for a week-long ski course in the blue slope group, along with his friend. He's a fairly good skier, comfortable on red slopes when we ski together. However, when they arrived, my son was placed in the beginner group and spent the first few days in the kids' area.

He came home on Monday, complaining that it was incredibly boring. We contacted the ski school, explained the situation, and asked them to check if he was in the wrong group. They said they would look into it, but nothing changed. He remained in the beginner group. On Friday, we didn't even bother sending him.

I feel terrible for putting him in that situation, especially since he was there alone, over an hour from home (we used their shuttle bus service). The Vreni Schneider staff has been very rude and unresponsive. My German isn't strong enough for phone conversations, and the person answering refuses to speak English, so we've been communicating via text. Now, they seem to be ignoring me completely.

We want an explanation and a refund. We paid for the blue slope group, and they clearly didn't provide that service. I'm unfamiliar with the consumer protection laws in Switzerland. Is there any point in contacting a lawyer in this situation? Any advice would be greatly appreciated.