If I were you, I'd consider whether you are interested in the calculus class because you probably will need to do a lot of catch-up work on your own time. I'm not understanding the issue of your Spanish IV class, so I would try to get more information. If you really want to take it, then try to argue your case, especially if it is open to other students. Unfortunately, this all seems to come down to staff and school admin not keeping in touch or knowing what the other is doing.

You may find that your schedule changes after a week or so. This does sound a bit odd, however, during my 3rd year in university, there was a huge screw-up with the online course registration system. Fortunately, I managed to maintain my schedule. For a different semester, the university did another change in which it evaluated which students could be allowed in based on their academic history, GPA and majors. Unfortunately, this was only announced after the first week of classes, so some students got booted out and scrambled to find another course. This time I was affected and had to enroll in alternate courses.