YES - the relevant authorities can require applicants to take a language test. But these rules should be applied proportionately, and it should be possible to make exceptions to take account of individual circumstances, e.g. if you have already lived or worked in a country using the relevant language.
POSSIBLY - national governments have sole responsibility for recognising academic qualifications. The European Commission can take action only if:
The ENIC-NARIC (a Europe-wide network for recognition of academic qualifications) centre in the host country may be able to help by contacting its opposite number in your country.
That depends on the country, the university and the course itself. As a general rule, you should have:
Get in touch with specialised assistance services