Labour laws clearly state that the company that takes you in as an intern is required by law to absorb you as their full time employee, paid in their scale and entitle to leave days among other benefits. If they cannot do that, then your internship should end at the end of your third month there.
Las leyes laborales establecen claramente que la empresa que te contrata como becario debe, por ley, absorberte como empleado a tiempo completo y pagarte según su escala salarial, así como darte días libres entre otras prestaciones.