Help! My sodastream is going crazy?

[Fartleking]

It won't stop gassing even when I'm not pressing the button. It's really cold now and I can't touch it. We just got a new refill today.

I've put it outside. I was paranoid it would explode 😱

It's now stopped, having discharged all it's co2. The container is completely frozen. That was a quick £12!