how can i determine that? right now i have two active cards, the visa and the master, so i'm thinking that it was NOT converted, just another card was added.
Did you ask to have the visa converted to a MC? If yes then that's what happened. I'm not sure what you mean by still active, is it still usable or just still showing up online? IME it was showing up online as a mirror account (meaning every transaction done on the new card was reflected on the old as well) however it was not usable.
The point of converting is not to get the 50k on the converted card it's just to allow another visa app to go through.
You can call and ask them whether the visa is still active or not.