Upgraded credit card, now previous card has charge

I was contacted a while ago to upgrade my gold credit card to a titanium one as \I was chosen as a good customer"and I upgraded. Upon receipt of my new titanium credit card the gold card was destroyed (cut) at the branch I collected the titanium one. I was told that I go on as usual and everything will be charged to the new titanium card as the upgrade was successfully completed. Now about 6 months later I receive a sms confirming that my credit account facility has been cancelled and if I use the card it will be *****. I phoned the allocated number on the sms and spoke to a consultant who told me that some charges was not changed to the new titanium card account and there is still R3000 outstanding on the gold card. Now"