Surface: anybody charged twice?

I pre-ordered Surface RT from the UK on the 25th and have just checked my bank account.

The Microsoft Store transaction hasn't appeared yet, and the money not taken from my balance - but my available balance is £1,118 short.

Obviously I expect the £559 I have paid for the Surface to be unavailable, but £1,118 is double that - Microsoft have clearly charged me twice.

Has anybody else had this problem?