Here's my story:
My brother was at his job at the mall (he sells RC toys at a kiosk), and a man who was looking around told him that he liked his, I guess, "sales man skills", and offered him a job at his bussines. But my brother likes his current job better, so he told him that he would tell his sister about it (me). My brother told me the bussines was a sort of small call center, but that was all he said.

So I called the man and left a message telling him I was interested in the vacant position. Then he called back, and I wasn't home, so my mom answered and the man told my mom that it was a private charity and that they called people and asked for donations, etc. So it's basically a telemarketer position.

I am looking for a job, but do not need one desperately. I really DO NOT want a telemarketer job. But I still need to call the man back. How do I tell him nicely, "Thanks, but never mind, no thanks" ?

Please give me your advice. Thanks in advance! :]

PS> The tittle says "turn down", but I haven't really been offered a job yet, I just want to let him know I'm not interested anymore.

White lies are often used for this scenario.

or you can just be honest and say that you are not interested in this kind of position. You are likely to run into this problem countless times in your lifetime. It is best if you start to deal with it in a mature way.