eBay Charged more for an item was for sale

[hashtagcurios]

We sold an item yesterday that was for sale for £150 plus £5.49 postage. The customer has been charged £155 plus the £5.49 postage and wondered if anyone else had seen this before? They live in the UK so was not related to any international taxes. We've given them the £5 difference back but surely this shouldn't happen with the amount actually charged to the customer being different to the one on the listing.

[*guinevere*]

I've looked and looked but I can't find them, sorry. I seem to rremember that at least one other was for £5. It seemed a bit too much of a coincidence.