What's my entitlements re: P60/P45 and other rights - Need help!?

You have no right to be offered the job above other people. in the tourist Industry which is usually quiet during off peak, it is up to the staff to contact early on in the year. You handed in your notice so someone might not have sussed you wanted to return. You need to contact whoever does the payroll, either by phone or letter and ask for your P45. You can start another job without one.