i must admit that i've never spoken to ebay Customer Care on the phone - but is there a reason why you're dealing with the US and not Australia? after all, it seems like all your products are australian (ie purchased here) and that your account is australian? 

i've always made a point of speaking with people via email or via online chat and making sure i keep a copy of the email or chat transcript. 

have you tried requesting a callback via ebay Australia and seeing how that goes? a lot of users on the boards here seem to be of the opinion that you get a higher level of service via using the call back feature as opposed to calling them yourself. 

you definitely shouldn't have to go through uploading these documents time and time again. it does sound incredibly dodgey. that being said, a lot of the time you do get copied-and-pasted responses from reps or they don't know what they're talking about because they're just picking up part of the story (ie probably seeing that something on their end says you need to upload x documents and haven't looked at the full history). 

i'm by no means an expert at all on these types of issues - but i'm sure someone here will have the best advice for you about what action to take from here. what you're currently doing though obviously isn't working. 

i really hope you can get the problem resolved as i can only imagine how frustrating it is for you. 

** edit - i did see that you said you have tried writing to ebay australia and calling them - but something seems to be wrong, because i highly doubt you should be speaking with people based in the US on the phone regarding this issue (?)