Quit my old job a couple months back and on the day of my last payslip I was payed 20 pounds despite being owed multiple days of holiday as well as a full days shift. My friend also quite that same month and had the same issue so messaged inquiring about it and getting little response. I then decided to message him asking about it and he said he would contact payroll to see what was up. He didn’t follow up within a week so I messaged again asking if they had responded and he simply hasn’t read the message but I know he actively uses the app that I sent it on. What can I do to get these wages?