Is the dream holiday competition a con?

We tried to take part in this Coke dream holiday competition not once or twice but many times. On every single occasion after following the instructions to the letter we get the same rejected response

“Connection problem or invalid MMI code”

Now we have tried at 3am as well as more normal times with precisely the same answer. We are left with the distinct feeling that there is a con on the go and Coke is deliberately preventing us (and everyone else we have spoken to) from entering.

Personally I would be surprised if it was a con, but given what is happening around us here, not impossible??

Colin