"email contact"

I have an appointment booked at St Thomas' endoscopy unit for tomorrow. I'm currently unexpectedly out of the country and have been trying to contact the hospital via the website and various email addresses for the past three weeks. But have had no reply whatsoever. There is a specific 'making, changing or cancelling your hospital appointment' webpage set up that says I will get a reply within three working days - I've used that twice and had no response. I've also tried a complaints form online. No reply. I even emailed 'PALS' and am still waiting a reply. I have no idea if the hospital know I'd like to rearrange my appointment or not. It is set for tomorrow and I've heard nothing back from any of these multiple attempts to contact them. And am very frustrated with the awful service via anything other than the phone.