Brother, settlement visa is the most thorough visa in any country, both for the checks it takes and the rights it grants. if you can have that one why bother with the much inferiour "student visa"? The settlement visas give all the rights all other types of visas combined, i.e. work, renting a home, etc.
I must state that this is not a strictly legal case, or advise because of that. Unless you were refused without a legal reason that is. Therefore the best way to solve it is to work with "foreign police". They know the practice better.