Hi booba22,
As you can see my timeline on the left panel under my profile name, i have been pretty successful with my application so far
Be assured that the process of pushing the application date to the latter date when an addendum document was received is not followed in the current fswp bcos my ecas status shows my application receive date as 5th june itself and not august date.
Be aware that it is not garanteed that ur addendum document will be added to ur parent application. But u can always try ur luck. I see that u may be a little late for sending a new payment instrument as ur application may have finished completeness check and moved on to cost recovery section by now. It has been observed that cic requires quite some time for the additio process. But u have nothing to loose in trying ur luck.
I would suggest for u to try using ur old card to shop online for something in canada. See if that works. This will provide u with a good measure if cic will be able to use old payment measure.
Regards...