Go, Pat!
If you are the admin dept, I'd agree with whoever it was described "redundancy" as inappropriate. It sounds to me as though your predecessors (all "sacked") and you have been "retrenched", as the admin will still be required and thus the position filled. People are never redundant; it's the position that's redundant. Different industries and different jurisdictions (I'm writing in Australia) have different terms and payout procedures so I can only agree with those who offer you support.

Cheers, Rowan
who is secretary of the local branch of his union but can't be of more help