Who called from 7182936900

called and said 'call extension 521'. i said 'extension five twenty one?' and girl said in a not-too-nice tone 'five-two-one' then hung up.
weird.

I'm in Ontario Canada.

Called and left message on my cell phone.  Black female voice said, "Hi this is from Cal Auto Mall returning your call.  My ext. is 4619."  I ain't gonna respond!