I think it's more of their tape-recorder style that puts me off, otherwise I read Islamic books regularly, and watch Mufti Akmal on QTV buht shauk se!
But still, I think you should respect them, and just TALK to them like a mature person, or just tell them I can be here for 5 mins. or whatever you want to say, but dont lie.
It's their "GHERNAY WALA STYLE" that really irks me. I mean ... if you want to invite somebody to religion, do it with WISDOM and intellect. You have to talk at the level of the person you are talking to, not just turn on your latest BluRay ratta byaan and expect the other person to respond, duh!
Lekin phir bhi ... I think they are sincere in their ways, and want good for you/all of us. We must treat all with respect, whether we agree with them or not.
We are all too stuck in our own little worlds that when someone different walks into it, we find it very uncomfortable. However, if you are intelligent enough, you'll allow for other point of views in your life ... but to agree or disagree is ur choice! (as long as it's not against Shariah).