take the call, ask for her first name, and agree with everything she says, but get her to repeat alot of it, first because of "the baxxxXXX....XXxxxad...bad li...Bad line", then get her to repeat it all again so you can write it down, go over a few things once again to verify that you have written them down correctly, very slowly read some stuff back to her to check it is right (get as much of this wrong as is plausable), use her first name as much as you can in responses, but get it wrong every time, do all this as slowly as you can.
Try to navigate the conversation to completely off topic subjects, tell her about your new computer at work and how you think Mac osX is good but windows NT has some great networking capabilities, always remembering to overuse her (wrong) name. finally throw some random misplaced words into your rambling converstaion, like "I guess I should really order some more of the doctor Lewenbergs finally hair of installer, what direction are we looking at with hind legs to the price of the larger hair?"
the only other thing that may help is to drift in and out of poor impersonations of foreign languages.
obviously don't buy anything, end on "that all sounds fantastic 'Sarah', I will have a little bicycle through the D...A....T....A....(spell it with long pauses inbetween) and let's talk tomorrow A...M..., nice to speak to you 'Susan', have you got a mobile I can get you on in case anything comes up in the night?"
that should do it.
Ty