Aside from a refund which it doesn't seem you asked for (so you could purchase from another retailer) I'm not sure how you expected that to be delivered. I do recall this problem coming up before (wasn't it GWR?) but IT fixes aren't quick - the only thing they could have done quickly, and maybe should have done, was to block adding to Wallet to prevent any confusion until fixed.
Pursuing a refund of 40p is something that just doesn't seem a sensible use of your time.
I'd see you as having had a good case for some fairly chunky compensation if you'd been refused travel on the Wallet ticket, but as this was caught before travel and a method was used whereby you could travel I think this is really quite tenuous and just one of those annoying things. Just cease giving their booking site your custom and pick another if you're annoyed with them and want to hit them (lightly) in the pocket.
The TOC was first contacted about the fault ~4 weeks before the first journey and ~8 weeks before the last. I do feel like there was suitable time for them to try to put a fix in place. Alternatively, seeing as it was all tickets under the same booking reference that showed the same time they could've maybe tried something like booking them separately, and linking the bookings to my account. Individual bookings have worked for me since, just seems to be the issue arises when multiple journeys are added to the basket. I don't know how these things work, but there must've been something they could've done.
Again, I'm not pursuing the refund of the printing costs. Rather a price reduction to recognise the contract was not fulfilled (as outlined by
@Watershed 'the provisions of consumer law may well entitle them to more: indeed, I'd argue they do') and then a Gesture of Goodwill to recognise the inconvenience faced over the ~2 month period for having to get in touch so many times, and the poor service experienced etc. They are unlikely to agree with the gesture of goodwill, but they should agree with the price reduction now I've quoted the relevant consumer law sections and this should be more than 40p.
To be honest, I wish I hadn't highlighted re the incorrect times to the TOC and rather just travelled on the tickets as I bought them on the right trains. The problem is, if someone then took my details as they deemed it to be invalid that's just a whole can of worms that is best to avoid - even though anything should be voided/refunded on appeal given the circumstances and that the tickets were actually valid.
I will cease purchasing from them not because there would be a
tiny revenue loss, but because there clearly isn't any kind of desire to assist the customer from the back office teams. The general CS teams I spoke to were friendly, but they had to pass it to this other team that just didn't help at all. Then the after sales team I spoke with weren't understanding at all, and just raised it as a complaint because (it felt like) they could've really be bothered to look into it.