yup same here, but with me it happened when I shopped through the UA shopping portal. I made a couple purchases, got points, they were transferred to my MP account, I returned one of the items, and the appropriate miles were deducted from my MP account.

SO i'm sure the same thing happens with UR. It's all about the order number. That's what cartera tracks. If the order number shows that the item has been cancelled or returned, it triggers cartera to deduct the miles. the process of course takes a few weeks.