"Waiting times"

I have been under the REI for a few years and never had a bad experience the staff are lovely and the consultants excellent. However the waiting times for follow up appointments and reviews are horrendous my last appointment was Feb 2017 the consultant expressed concerns regarding my optic nerves and said he wished to see me in 6 months time. It is now June 2018 and still no appointment have rang up on 3 occasions to be told there is a backlog. This is very worrying especially when it concerns ones eyesight.