"Appointment with the wrong doctor."

I was told by my doctor that they were going to test my blood for certain things and that I should make a follow up appointment a few days after the blood test to discuss this with them.

When I turned up that day I found out that the appointment that the receptionist had booked for me was actually with a completely different doctor! I have quite bad anxiety sometimes, and really find it difficult so speak to new doctors or new people in general and I found myself panicking slightly as I was sitting in the waiting room. I was quite annoyed that I hadn't been told about this previously as apparently my usual doctor was on leave that week. 

The other doctor was great, I am not questioning that. But I feel like there should have been more communication present about which doctor I was going to see when I booked the appointment or at any point within the weeks that I was waiting as I found it safe to assume that I would be following up the test results with my usual doctor.