I am glad to hear that the camera has been treated well.
The A/V port being loose might signify some damage inside the camera. Or, simply, a connection of the memory card slot to the rest of the circuitry, being either loose or cracked and thus producing the 'BUSY' message.
I think it is a safe assumption that your camera will require repair if it is to work normally again.
Of course, you might prefer to replace it instead. That is up to you.
But to have your camera repaired, given it is out of warranty, would mean you would bear the charges for that repair yourself, unfortunately.
To start the repair process, go tohttp://www.usa.canon.com/cusa/consumer?pageKeyCode=onlineRepairLanding
and fill out the form and submit it.
(For any repair, of course, it is advisable to get an estimate on the repair charges - if possible - before committing to repairs.)
(And of course, if you bought an Extended Warranty plan with the camera, then it is still within that warranty and that will pay for the repairs - if that is the case.)