If im 10 mins late to my appointment I "missed it ...

If im 10 mins late to my appointment I "missed it entirely" (I live 45 mins away). If I do a walk in I have to wait for over an hour for them to be sure the next appointment is missed before I can be seen. Even while I watch the doctor have no patients and walk back and forth alone.. If you question the staff they become very short and rude with you.