Cheers all. I'll email them, see what happens.
I actually bought the strings from Amazon but by the time I'd put them on the bass my 4 week returns window was passed.
Does anybody have a email or telephone number for John Hornby Skewes? I bought a set of Dean Markley Blue Steels that has a duff E string.
I emailed Dean Markley who apologised and suggested I contact JHS, but couldn't give me an email address. The JHS website isn't much help - I've messaged them via Facebook as suggested but no reply.
It's a bit far for me sadly, but having looked on Google maps the first thing that pops up with your postcode is an establishment called LOVE LIFE, EAT CAKE. I'm sure they'd be happy to cater any meetings!