1-(866) 892-2253 is a legacy TWC number that will take you to the IVR, it is a current number and can be used for any support needs. CableCard support can be reached directly at 1-866-532-2598. Calling the direct number should get you to the CableCard trained agents much quicker.
I am in a TWC -> Spectrum service area and this one worked well for me November 20, 2017 when I had tuning adapter issues effecting service through my Ceton :
Please let us know which one may have worked for you.
It would be nice to have some "official" word as to what the proper current number is.
I recently got an HDHomeRun Prime box and a CableCard. I attempted to activate the card online at https://www.timewarnercable.com/en/support/tv/topics/cablecard-pairing-form.htmlwhich successfully paired the card with the box but never activated it. The box shows Card Validation "none". I then called 1-877-772-2253 and SPECTRUM attempted to send the activation signal multiple times but it never worked. Any way to escalate this at SPECTRUM to get this card activated? Thanks You