The problem here is the transaction was recorded as Completed in the site yet you still haven't received it. That would be really frustrating in the part of the user. Have you tried contacting CEX account here? Tell him that few weeks have passed already and still no update after this "they escalated my issue to the concerned department". Sending them a tweet (@cex_io) might help too.

Several threads are popping out about CEX.IO these days, I wonder how many tickets are they receiving.