you just call the main customer service number and ask for the Digital Department aka Website Tech Support.

I suggest telling Customer Service that you’ve already spoken with Digital and they told you to back when you had more time etc. Otherwise you might have to waste time tell the whole story to customer service and wait while they look into it etc.

UPDATE NOV 6TH: I called them back to make the transfer, and could not do it.
First I got transferred to "Digital" who said they couldn't do it and would transfer me to "Travel" even though I asked them not to because I've been down that path before, and Travel only issue tickets, they do not transfer points to partners.

Having explained it all over again to "Travel", they transferred by back to Cust Service. This time I talked with someone who knew how to do it.

But then she tried entering my Turkish FF#, and her system said "invalid format". She explained it is a plain text field with no formatting pattern etc. She tried the number, she tried it prefixed with "TK" (as it shows when I login to the TK site, she tried with hyphens, spaces... nothing worked. Then I asked her to try it with Cathay and with Singapore. Same error message each time.

She reached out to her backend team (aka "Digital") and she siad they were very unhelpful and told her they are not able to do this (the opposite of what someone in Digital told me last week!)

By the way, she also had to verify me by sending a one-time code to my T-mobile number, and that worked.

So, I'm stuck, I can't do anything. Capital One Venture sucks.