Trading Standards only get involved with buyers problems, not the sellers. They won't be interested and have no clout with buyers.
I've been thinking about this some more, Ratter. Not only did you fail to notify the buyer that the order was ready for collection, you failed to follow it up with another email or phone call to arrange collection.
You are probably right in thinking that the buyer had changed his mind and was looking for a way out but I think you have little choice but to refund. The