So I just had my first "loyalty call"; someone from 2D calling to upsell me to Pay Monthly.
Even with a direct "I do not want to change my plan, I am happy with Pre Pay", they kept on the sell and then to top it off - asked me who I was with for Internet and tried to change me over to 2D Internet as well, who I am already with.
By the end of the call I was fuming and I told the person never to call me again trying to sell me stuff.
Note to 2D - this is how you lose a customer, not make them spend more.