Programatically you are pretty much stuck...it's probably a proxy filtering, which means:
Internet <=> Proxy <=> You
That when the site gets to the proxy, the proxy says no... and you (more than likely) have no other way to connect.
There are probably roundabout ways around this, but your best bet (and safest) is to explain your case and try to get things changed.
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"But what of all those sweet words you spoke in private?"
"Oh that's just what we call pillow talk, baby, that's all."