Flightsafety and Oxford are particularly unhelpful to non-students of theirs. My experience (and that of others I know) was you could not get an appointment for months with them - if you could even get a call back. Get it done in the US if you can.
To be fair thats because it was not actually them providing the service, it was an employee who was American doing it as a sideline. The fingerprints can only be collected by an approved US Citizen. The guy at Oxford worked in IT and did it on the side, from what I understand the situation at Flight Safety was similar. I assume he has now moved on which is why you are not getting a response.