As I mentioned yesterday, this problem didn't emerge within Barclays, it was caused by problems with another bank that affected customers of all banks.
"One of our competitors has had a challenge with their Point Of Sales (POS) systems, which has led to them submitting previously approved POS transactions weeks after approval. They will be issuing out a statement to this effect soon. In the meantime we would like to encourage our valued customers to use Barclays POS swiping machines where we have these at all times.
We sincerely apologise to all customers who have been affected and remain committed to improving your service experience with us."