"I am trying to change my appointment."

Anything else?

I have a dental appointment to take my wisdom teeth out on the 27th November. I have been trying to get through to the dental department to change it but I cant get through. The operator even said she has problem as they don't answer the phone. I don't want to miss my appointment and be discharged back to my dentist and have to start this whole process again. So can someone help me. Many Thanks