Charged delivery twice!

We did a layby on several occasions, and today we paid off the laybys that will be delivered at the same address. Bradlows Mdantsane City Mall charged us twice for the two things. Before we paid, we advised them to cancel the one delivery price because both things were heading to the same house. To our amazement, the sales lady consented, but charged us for two delivery. And they refuse to return our money for the second delivery price they charged us.