"No contact from the Orthopaedics Dept"

I have been trying to get a follow up appointment with the consultant for almost a month. My op was carried out in June, a three month follow up appointment was promised.

In the first couple of days of September, I received a letter dated 15th August asking me to phone and book an appointment. Since then, I have been ringing at least three times a week to do just that. It either rings and rings until it cuts out or very occasionally I get an answer phone message saying ' we are busy dealing with other patients'. I need this appointment; the issue which was healing well has flared up, I am heading for a frozen shoulder and am in a lot of pain. I will now be ringing every day, as often as I am able. I do not want to take time off sick from my NHS role due to this issue but I am almost at the point of being unable to drive again - so even more pressure on my NHS colleagues then?