"extremely disappointed"

I rang the surgery today (29th March) at 10.05am to book an appointment after receiving an email from the GP telling me to do so - to discuss a form that had been sent to me in the post that I had filled out. The receptionist told me she didn't understand at first but then after I explained again, she told me there were no appointments available today and that I would possibly have to ring back tomorrow but she would check with her supervisor, she came back telling me that she could book me in for a telephone appointment but only on the 20th April! 3 weeks away! I asked why it was so far away and she said that the pre-bookable appointments can be anywhere from a couple of days to 4 weeks away and that because her supervisor had told her it wasn't urgent, that the 20th was all she could give me. I was shocked! firstly I had already spent 17minutes on the phone trying to get through - listening to the awful hold music and a woman's voice telling me my call was important - clearly not if it takes that long to answer! and now being told that I am not urgent enough to get an earlier appointment. I can understand how busy the surgery is, but I do not think anyone should be having to wait so long for an appointment, I would not be asking for one, if I myself did not think that it was urgent. I feel incredibly let down in a service that is supposed to be there to help and care for people.