As I have a Barclaycard credit card, they send me letters every now and again to make a new free balance transfer for another year. This time I called them and the conversation went like this:
Staff: "I believe you are calling about your balance transfer offer?"
Me: "yes, is this balance transfer offer for the same credit limit I already have or will I get a bigger credit limit?"
Staff: "it's for the one you already have"
Me: "oh ok, in that case can you please stop all marketing coming to me"
Staff: "yeah, that's fine"
20 secs late
Staff: "I have stopped all marketing coming to you and because you did not get the answer you were expecting, I have put £5 into your account."