I had the exact same experience and the "support" person was of little help. Sadly I have not much to offer other than commiserations. I adjusted the '52 weeks' amount so that the Holiday Pay balances were correct-ish and have been running my old (reliable) payroll alongside to make sure this new nonsense is making sense. I did discover that you can adjust the annual earnings figure when paying Annual Leave to make the rates match what is in my old system.
Now I just need to figure out how to make deductions for staff accounts....
Oh no that doesn't sound like I'm going to have an easy time sorting this then. I can manipulate the numbers to make the leave balances match but that changes the other figures (accrued, advanced etc) incorrect, which maybe an issue, if an employee leaves, when calculating final pay. Eeek.
