By this afternoon I'd had no reply so gave them a ring. The guy I spoke to said he'd speak to his boss & that it shouldn't be a problem to get a £30 refund, it would go back on my card next week. I said I'd be happy at that but I'd also be just as happy to get some extras instead. So he rang 'Sewing Machine Steve' then rang me back to say they'll give me more thread and some bits and bobs, which I was happy with.
They're giving me 16 spools of thread (1 red, 1 blue, 1 green, 1 yellow, 4 black, 4 cream and 4 white), it's moon thread which may not be the best but it will do for now until I get my stash of good stuff.
Also getting extra needles, some retractable tweezers and he said he'll have a look at what else he can chuck in that may be useful to me. He was actually putting all these things in a bag while he was talking to me. Granted it won't make up £30 but not far off.
I'm pleased with that anyway