You are wrong. "Their" was the proper usage. It indicates the possessive. "They're" is a contraction for "they are" which is not what is being stated in Mark's sentence.
I subscribe to Morningstar online. I really don't appreciate them calling my mobile, since I didn't give them my number and they obviously looked it up. As much as I respect Morningstar as an investment information company, I'm going to cancel my subscription now.
EVERY time they call our office, they NEVER say anything- as soon as they hear my voice they don't say anything, they just hang up the phone EVERY TIME they call....ANNOYING! Does this happen to anyone else?
Got a call from them this morning. They asked for me by name, then said they wanted to talk to me about the mortgage on my house. I told him I was on the DoNotCall list and why was he calling me? He said, "uh, um, let me check on that" and hung up.