Jimmy-T may be right, that you could challenge the validity of the proxy forms, if you can show they were signed and dated with a blank name of the recipient of the proxy, which was later filled in. I suspect this is a common practice, and the Tribunal may or may not find in your favour if you ran that case. Also, the purpose of a proxy is to permit anyone to act on behalf of an owner, and it would not be too difficult to arrange for valid proxies to be made out to the current management team, with a little more effort involved.
Nevertheless, that would still leave you with some valid proxies, and some owners voting for the current management team. Have you got the numbers to out-vote them? I would suggest you do what your opponent have done – contact all the other owners, put a valid case to them to elect a different management team, and rally the majority of owners in your building to elect you and your team of owners.
Your assumption that only the secretary of the strata committee has access to all the owner’s contact details is not correct. Any owner can get access to that information, although you may need to pay a small fee to do so.