"Time frame for surgery"

My husband was seen by Neurosurgery Department in May 2014. Everyone was very helpful and Doctor who examined him explained fully about the surgery and answered any questions without rushing us. We were told surgery would be around the end of the summer. Pre assessment appointment was arranged for 19th of August and again the hospital staff were very helpful. We were told surgery would be scheduled within 6 weeks unless there were any problems with the pre assessment tests. It is now over six weeks and no surgery date has been received. My husband is in a great deal of pain and anxious to have this surgery. On the advise of his Rheumatologist I called 4 times to try to get information regarding surgery. No one returned any of my calls. I then emailed and this was answered saying there is a backlog of surgeries and therefore no date could be given for my husbands surgery. In the meantime our life is on hold waiting for a surgery date. I am also concerned that the pre assessment appointments are so far ahead of surgery and does this now mean it will have to be re done if surgery is not completed soon? It is very frustrating.