I don't understand your question. Any credit cards you had when you went bankrupt had to be declared to the Official Receiver and you would not be allowed to keep them. If you had one and did not declare it there is a problem. You have not abided by the requirements and your discharge can be delayed and possibly other action taken.
Once you are bankruptc you cannot get credit of more than �500 without informing the potential creditor that you are bankrupt. Also, lenders do CRA checks before giving credit cards and your bankruptcy would show up and you would be denied a card. So, if you did get a card after becoming bankrupt how did you do it?