No hablo español.
It depends mainly on what you have signed with your bank.
Are bitcoins different from any other product?
Have banks a legal base to freeze your account if you follow AML and fiscal regulations?
True, if you have an account they can't keep your money for following regulations. But they don't have to let you set up an account in the first place, if they don't want to, and if they kick you out
and return all your money, that is not illegal either.