First of all: don't worry! We're not going to debit your account twice for the same transaction. It's perfectly possible that the amount is still in processing, but your account has already been debited. This is because the bank doesn't always let us know that the amount has gone out of your account very quickly. After a day or two, the status will change to "paid". You don't have to do anything extra for this.
However, your limit will still be affected by that transaction. Unfortunately, we cannot adjust this manually for you. If necessary, you can increase the limit by (temporarily) topping up your account balance until your limit is adjusted/restored.