"Impossibility of contacting Endoscopy Appointments..."

On 16/2/15 I needed to cancel an appointment for a colonoscopy the following day through illness. I called the contact number 0207 288 3822 several times during the day without success. Nobody picked up the 'phone and each time there was a message asking me to leave my details and I would receive a call 'shortly'. In the course of the day I left 3 such messages and I am still waiting for a response 2 days later. When the Whittington is good it is very good, when it is bad it is terrible.I can't give this experience any stars.