It sounds like there is a communication breakdown between managers and payroll, managers and HR, and managers and yourself (not at your fault though). Your manager hasn't notified the relevant departments of what needs to happen, or contacted you (or whoever contacted you re your return) in regard to the meeting BEFORE you were due to return.

You could maybe have a chat to Industrial Relations / Fair Work to see if there is anything they could suggest. Otherwise I would suggest speaking with the manager you spoke with prior to leaving and if they don't come up with a suitable solution, is there the ability to take it above them? You may not be the first person who has had this happen.

Hope it can all be sorted. Sorry I'm not of more help