If everyone did what I do these calls would soon disappear.
Whenever I have time I engage them in long conversation pretending to be interested, eg: asking them to speak English, asking them to repeat something, pretending to misunderstand etc etc.
Finally when they think they have me hooked, they transfer me to a supervisor.After I have repeated the lengthy process, the supervisor asks for my credit card details. My reply is that my Dad wont let me have one cos I'm only 12 years old!!!