keep in mind that the current president it deporting many many thousands of immigrants without cause many are in “concentration camps “ awaiting deportation, they are probably advised to deny anyone who might try to stay
apparently not or they wouldn’t have turned you away, unless there is more that you aren’t telling us, otherwise you wouldn’t be here , but rather you would be straightening things out with official
If I understand correctly, your visa isn’t in force until april, yet you wonder why you can’t just do what you want in spite of conforming to the rules?
Passport actually gets stamped anytime when clearing immigration in any city iit often is forgotten by the tired, bored or distracted human behind the glass!