Wingback seat heating help

[R55ENS]

Hi everyone. I fitted some wingbacks to my VW Transporter back in Feb and have just decided to get the seat heating working. Wiring is all done and I've managed to get them working to a point. Passenger seat warms up nicely, but I have to bypass the base on the drivers to get the backrest working. This leaves me to believe that the heating element in the drivers base is dead.

Now here's my question, can you still buy new heating elements for the seats? If so where can I get some?

Also, can you get new foam as the drivers outer bolster is gone. Or can would a retrimmer be able to make them?

I've never had seats retrimmed so wanted to make sure I had everything they need as don't want any issues!

Cheers