We understand your frustration, but unfortunately can't offer any solution.

In our case it would be just as annoying as couriers don't deliver to us (we don't even get Australia Post parcel delivery, but are happy to pick them up from the local post office 25km away).

We wouldn't even know where the nearest courier depot was, but it would be at least 100km away & cost us in both fuel & a wasted day driving there & back.

So we only buy from sellers who are prepared to use Australia Post as an option, as would many other buyers for a number of reasons.

Hope you can work it out with the seller.