No, though I've had to deal with colleagues, students, and other people pretending - or greatly exaggerating - not understanding english. It's quite common for students on placement in my kinder/childcare room to have issues with understanding the nuances of a lot of the language used in the early childhood field, since this can be hard for native english speakers to pick up, too. There's a lot of jargon used, which will always cause problems for those still learning the language. Every now and then there'll be a student who *does* understand the actual words and demonstrates this understanding, only to claim not to understand if called up on anything - even when there's no problem, just something needs to be said about doing ___ this way instead of that way. Sometimes it's definitely the student trying to pull one over on us (.. we work with toddlers for crying out loud, observing patterns of behaviour and making judgement calls is literally in the job description.. but I guess there will always be some who try and cut every corner they can.. no matter how many times they get caught). But I've found more often that it's simply a reaction to being stressed that has ESL speakers frequently fall back on "I don't understand". Once we deal with the panic that they have done something really wrong and are "in trouble" (presuming they haven't and they're not), they can relax and just concentrate on following the words spoken and working out what we mean.
I used to be part of a group that ran an annual anime and pop culture festival. There were strict rules regarding "bootlegged" (knock offs of licenced items such as pok?mon toys, dvds, clothing, etc) and weaponry including cosplay props (Victoria has the strictest laws in Australia and police actively enforce the law at these events in the interest of public safety). I used to get called in to help "talk to" various traders who somehow lost their ability to speak english *right* when security and area co-ordinators needed to explain why ___ item must be removed from the booth immediately or they would need to leave. I rarely got to do anything useful on these occasions though - the downside of being a trader at an event where the organisers know everyone, and most speak or at least understand 2 or more languages is that a ruse like "I don't speak english" tends to fall apart pretty quickly. Especially when the trader spent an hour chatting with the co-ord's girlfriend yesterday..
I don't have much trouble dealing with people trying to sell me stuff at shopping centres or on street corners, though I certainly get a lot more attention than my partner does. The only time they ever approach him is with me, which is always stressful for him as he realises how lucky he is to avoid that hassle most of the time. But I don't mind, I usually make eye contact, smile, shake my head and say or mouth "no thankyou" and keep walking. If they make a comment I'll always reply, even if it's just to repeat "no thankyou" (which I say regardless of whether I heard them or not, as I often can't hear what is said in a crowd or where there's a lot of background noise).
I have so many friends who've done that kind of work. It sucks, for everyone (except the company that rakes in easy money from this type of "employment") but I personally am not going to knowingly contribute to someone feeling invisible/ignored when they're just doing their (crappy, terribly poorly paid, with no entitlements) job. I'm also not going to be suckered into buying something, or donating to a charity that pays a commission. So I've found a nice compromise that keeps my conscience clear, and also lets me walk around with my nephew and other kiddos without risking being a bad example (since ignoring people speaking to you is rarely encouraged in children, it is a bit rich to then turn around and do so.. much better to model appropriate responses than to ignore the approach).
