Urgent question about enrollment/application for teaching?

I applied for the special education program at the University of Cologne. The registration deadline is midnight tonight. I was accepted and received partial admission. However, I only have this partial admission for combination A, which is what I applied for. Now I can choose my subjects and then enroll. The problem is that with combination A, I can't choose the subjects I would like to study. So I have two solutions. 1. I enroll in the subjects I don't actually want to take and then call the university directly on Monday, hoping that I can change the subjects or combination before the program begins. 2. I enroll in these subjects and hope that I can plan my studies so that I don't take the subjects initially, and then change the subjects/combination for the next application period. This way, I could already earn points in other areas, such as educational science, during this time. Otherwise, if neither of these is feasible, I will study special education at another university (my second choice)

So, my question is, is one of these two options possible? And: If I contact the university on Monday, will they be accommodating and give me another chance to enroll?