"Trying to book a colonoscopy"

I've been given the telephone number of Charing Cross endoscopy department with the aim of booking a colonoscopy.  I've already had to give up twice as the telephone robot told me the wait time was 11 and then 24 mins.  This morning I'm determined to get through.  Robot told me I should be answered in 15 mins.  Here I am some 38 minutes later and I still haven't been put through.  For the past 15 mins I've had the message we expect to answer your call in approximately 1 minute  over and over again.  It is incredibly frustrating,  I appreciate there are peak times for appointment booking but you must know by experience what these are.  Isn't it possible to allocate more resources to those peaks?