Unfortunately as long as you own the condo, whether you vacated or not, you're obligated to pay the dues. I don't know your particular situation of course or your HOA rules but you would have received a copy when you bought. Just be aware that most homeowners associations are very serious about dues. I've known many surprised people who were threatened with foreclosure when they were late, and they do have that right if they put a lien on your home. and they will! best to either pay it or if you really feel you have a case for not owing it for some reason, contact an attorney. I'm not exactly sure what you mean by "vacated" but if you've abandoned the property and letting it go to foreclosure, the HOA will likely be a lien. Of course your mortgage holder will probably in first position. I don't think they can come after you personally if it's foreclosed but again an attorney would be your best source for what your options are, and as a Realtor I can't give you legal advice.
best to you