Before covid it was a guaranteed to be next day delivery for express post within the network. I as the sender claimed it a few times over the years. During Covid they suspended it and I don't think it is guaranteed anymore, even now. But yeah, if it takes a week when it should be 1 day, yes I would claim it if it was still happening. I had a registered post bounce backwards and forwards for 3 weeks within NSW once, I rang up and complained and they even refunded the postage on that one even though it was not guaranteed. I too have always received all my parcels eventually and still reckon Aust Post is pretty good.