During the last two months, I have received responses from customer care within 21 days.

OP, did you get an email from CC at the time of your initial contact?. If so, it should contain a reference number.
I suggest you call customer care, where you are now likely to be connected to a live agent fairly quickly, give
them your reference number, and see if they can respond to your request over the phone. Have done
this a few times and it has worked like a charm.