"Waiting times are appalling"

After having a car accident in July 2012 I have undergone steroid injections in my lower back in October 2013 and March 2014, both with some success but I was told that they would need to be repeated. After having a telephone call with a nurse from the pain clinic in October 2014 I was told I would be put on the waiting list to have the injections repeated. I moved house in January 2015 and rang the pain clinic and informed them of my new address (so I would not miss this much needed appointment) and was informed that there was a very long waiting list and I would get an appointment for March. Having called the pain clinic twice in past two weeks (and leaving messages on the answer machine) trying to chase up this appointment I still had heard nothing. So I rang this morning and was informed that the person who deals with the waiting list has been away on holiday and is now working elsewhere in the hospital and so no one could deal with this. I asked if they could check I was on the waiting list and I was told that the waiting time is now 7 months. When I asked if this meant I would have to wait a further seven months, they were unable to give me an answer. When I checked that they had updated my address (which I gave to a human being on the phone two months ago) they had not updated it on the system so I can only hope and pray that I have not missed my appointment. I have to put up with horrendous back pain and this is the only treatment that gives me any relief and I cannot believe that this system is so unorganised and that people have to wait for so long for an appointment. I am surely not the only one. Can anyone offer any help or assistance? Please.