Do you not think that having invested €3k in you, through paying for the course that you (presumably) asked to go on, that they might want to get some value from that?
Was the course quite specific to the work that you do, or will it transfer easily? Did other colleagues who were looking for funding of courses get refused?
I can see their point, and to be honest blaming the HEO and personalising the issue won't help, it won't have been the HEO that refused your request.