Cannot book an appointment for Residence Permit in Aachen

I obtained a student D visa to attend a language course in Germany before enrolling in university. After arriving in Aachen (Germany), I registered my address and completed the Anmeldung process in Aachen. Following this, I was instructed to schedule an appointment through the website "https://termine.staedteregion-aachen.de/auslaenderamt/" (A - Z (Team 1, Team 2, Team 3)) However, I have been struggling to make an appointment for the past four weeks, tried at various times, mornings and evenings 7 days a week. But, no luck so far, I would appreciate any advice or information from others who have faced a similar situation.