My 16yo son was delighted to get a Saturday job as a KP in a local pub. He did his first shift and said that although it was very chaotic, he wanted to go back each Saturday. However, we did not hear from them, and then he got removed from the work WhatsApp group. Ok, maybe it did not work out. The problem is that it has been over a month, and they have not paid him for the shift. I sent them a nice Messenger message, and the pub blocked me! Then I sent an email, no reply. What can I do now? Even if it did not work out they legally must pay, right?