I am trying to translate a flyer which directs readers to call the "Center for Assistance" at the company I work for to obtain help with questions. I am inclined to translate this "Centro de Ayuda," but it seems that I may be able to use "Centro de Asistencia" as well. When is it appropriate to use Ayuda? When is it appropriate to use Asistencia? Is there a specific distinction between the two in this context?