"Hearing Aid Re-assessment"

Having problems with the ear piece of my aid so asked if it I could have an 'open-ear' version. Initially told they were not available on NHS. I pointed out the NHS site says they are. Grudgingly it was agreed I would be considered for an exchange of aid. Told I would be sent an appointment. Didn't get one so 'phoned - I am on a waiting list for an appointment - will be around 3 months or more before I am sent an appointment! Given I have never been re-tested or reviewed since I had them, over 3 years ago perhaps a speedier appointment could be expected.