This kinda thing shouldn't be happening. If you're going to pay your workers literal minimum wage you shouldn't advertise paying £9.50. For context, I live in London, which has a recommended living wage of £11.95, and I was paid £11 at my previous job which was very similar. This place charges £15 for entry per person and I don't think workers get tips. I'm also not underage, I'm 20 and have proper experience for what the job requires.