"Can't contact"

You have sent my daughter an appointment via post. She has an exam that day and I need to rearrange the appointment. I have called the phone number on the letter (01268 394 994) literally hundreds of times and no one is answering. There is no answer phone message, there is no diversion, there is no holding music or que. As an alternative I didn't expect web chat but there is not even an email address. The NHS complains people miss appointments but if you can't rearrange them, that what happens.