This is so common, all chasing each others backsides. When my DVT was diagnosed, the GP called an ambulance. After 2 hours it had not arrived. I contacted the surgery who repeated the call to the ambulance service. 2 more hours....Nothing. In the end, my next door neighbour drove me to the hospital.
I too wrote a stiff letter of complaint, and 2 years down the line have had no response at all.
May I wish you all the best for your treatment, I have to admit that the prospect of "Needle" and "Eyeball" in the same sentence has rather put me off the idea of breakfast :))
Hope it all goes well.