My guess, based on experiences in a completely different line of work, is that they will not want to get involved with somebody that they can't collocate in a position immediately.

If you are not qualified to work in your chosen profession here, most agencies will just give you the cold shoulder (to be perfectly honest, how could they find a position for you if you don't fulfil the requirements to work in your chosen profession?)

I am sure once you fulfil all the criteria that would allow you to work here, agencies will become more approachable.

You may want to call them, email is easy to dismiss, but no so is a phone call.