Is this a scam? Kantar and DWP

[BPCoveredInSpots]

Received a letter this morning (see photo).

I went to the webpage, entered the username and password (scrubbed out on the photo), neither worked. On the webpage I was given the option to email, which I did, but the email has not been recognised.

I then tried to ring Kantar (not using the free phone number on the letter), and they are incredibly difficult to get in touch with.

I have no idea if this is a scam or not.
Any ideas what I should do?

Kantar are on Twitter if you wanted to ask them.

I would maybe phone DWP - carers dept and ask them for advice. Just can't be too careful these days, with all the scams that are going about. Good luck.