I received this call from a Ramada Hotel.  They asked me if I was over the age of 21 and if I was using Master Card Discover.  I said no.  They also asked me where was my last vacation and how much I paid for it.  I thought it was kind of weird.

Was a phone system that said "I'm sorry, that's not a valid extension, please try again" so I pressed "0" to see what would happen and got the recording again, then pressed "123" and then it hung up...

I received a call from this number a few times and its really makin me mad! I say hello 2 or 3 times and it says "the ext. number is incorrect" like what the hell. Today I tried sayin front desk. And again she said "the ext. number is incorrect" so I hung up. Is there a way to stop this?

Yup. Ramada ORL FTL. "I'm sorry, that's not a valid extension, please try again" and then it hangs up.
Called on 12:24PM May 10. and another time which is not my phone's memory.

Call back, no answer.

I answered this, and when I noticed there was no one on the line (before anything else could happen), I hung up.  These are usually automated dialers.