WORK OWE ME �1300!! help?

So I work in a bar and am paid cash in hand weekly, but i'm now 6 weeks behind on pay, amounting to �1300. No contracts have ever been signed, and although i have payslips saying i'm paying tax I've now heard that i'm now not. I have about a month left there and am doubtful i'll get my money before i leave. Is there anything I can do from a legal view to get what i'm owed. I've kept a spreadsheet of hours work and what I've been paid to date. Any advice would be much appreciated xx