The 64GB variant is currently out of stock, however we don't know here what the status was at the time you placed your order.
The Sales Support team should be able to provide you with an update. You should get text/email updates as well.
Not the best news I'm afraid.
We're no longer stocking the 128GB iPhone XR (all colour variants)
At this stage, I'd suggest the following:
1) Contact our Sales Support and request to cancel the order
2) Contact our Sales Support and ask them to key in a new order with a different model (note, we still have a number of 64GB models in stock)
You can message the team here. You'll need to select, Personal → Mobile → Track your order
I am sorry for the misinformation. If you have any other questions for us on our side, let us know. Happy to help.