Folding seat, straps broken! L2 Trend

[Gav W]

First post, apologies if this has been asked before, 8 did a search and couldn't find what I need
Connect L2 trend, the single rear seat is stuck down. The black release strap is broken, the red one is intact. I have found what appears to be a small manual lever under the seat which seat, its attached to cables which run the right place so I'm sure I'm on the right track but pulling the lever underneath doesn't release the seat. On the working seat, pulling this small lever manipulates the existing strap so I'm sure it's the correct thing. Nothing happens when I pull it though, I've tried gripping the cable with pliers and pulling it further to no avail.
Advice please! In the short term, how to release the seat but in the long term, how to replace the strap so its working again
Thanks
Gav

[Gav W]

I can't be the only one who's had a broken pull strap for folding seats, surely?

[Gav W]

Anyone??