"Phone and emails have gone unanswered"

I should've started on a course of tablets back in October but after weeks of unanswered phonecalls and emails, I gave up. When someone finally contacted me, they didn't listen to the problem and made me come to the hospital for a face to face appointment despite my being told there was no need at the previous one. 

I came in for the appointment and finally found out the dermatologist I had been under was not available (it would've been nice to have been informed of this). The dermatologist I saw was under the impression that I had been on the medication since October which was incorrect. 

They prescribed me 2 months of the tablets then and I received a letter to say I needed a follow up appointment in 2 months time. 

That date is this week. 

I have not had a letter. 

Nobody answers the phone (and I am waiting on hold for 30 minutes or more every time)

My emails have gone unanswered. 

My medication runs out in 5 days. 

What am I supposed to do? 

The service from this hospital has been an absolute joke. If it wasn't for the fact I'd have to wait 3 months to be referred to another hospital for treatment, I'd never return here.