"Terrible experience trying to arrange an..."

I'd been given an NHS information booklet from the dental hospital which advised not to have any treatment within a month of a big event, eg a wedding. I was then booked an appointment within a month of my own wedding. Trying to rearrange the appointment was an absolute nightmare; I was given conflicting information by members of staff, told I'd have to be discharged and call back, then that I would be ok just to rebook, and then finally that I'd have to be discharged. After one phone call someone rebooked my appointment without consulting me on the time and date - it ended up being closer to my wedding, so obviously I had to cancel it. I've since been made to feel like this is somehow my fault. Fast forward to trying to rearrange the appointment... it's pretty much impossible to get through to the right department. For some reason I'd been referred to the sedation department; someone there said they'd look into things and get back to me, as apparently I shouldn't be dealing with them. Nobody has called me back. I chased it up and was told that, again, another appointment has been booked in without consultation on time and date. At no point has any two members of staff seem to be on the same page about their process and procedures. In all fairness I don't think the staff themselves are at fault, but there's obviously no communciation and no clarity. I have no idea where I am and who I need to speak to.