What to do when you want to research something your advisor does not want you to?
This sounds like you are mad at your supervisor, however, keep in mind that researchers are often very specialized in a particular field, and would have difficulties supervising a project in a different field, or using a method they are not familiar with. THerefore, if you want to do a particular project/work in a particular field/with a particular method, it's up to YOU to find a supervisor that has the matching expertise. Otherwise, you may indeed do what your supervisor suggests you.

Where I work, students have the opportunity to choose their own supervisor that matches their interests. If they don't, they will get assigned to someone. In that case, the students are warned that they may have to do a project that is suggested by the supervisor.

Sounds like it is the same at your place. And in that case, it is normal to do something that you don't really like.

Let me tell you, it's better to work at something you do like. Therefore, get out and find a supervisor that works in your field/method. And don't blame the supervisor for having his own interests.