I have found that it can be impossible to get through to Cunard UK on the phone recently.
One of the most basic rules of customer service/sales is that every unanswered call is a lost sale so Cunard is only hurting themselves by this.
I personally try to avoid companies that do not answer their phones as it shows one of a number of things,amogst others:
a) They are incompetent (as lots of people are calling to complain)
b) They have planned things poorly (expect uncertain service)
c) They are cutting corners to maximise profits (expect bad service and poor quality generally)
d) They are in financial trouble
Each of these is a reason to avoid a company or you could be throwing your money away for nothing.