Double charge

I recently cancelled my Virgin Plus service and paid the remaining balance by credit card.
However, yesterday, the same amount was withdrawn from my previously registered bank account. I believe this is a double charge.

Earlier, I received an email stating
We received your recent pre-authorized payment of $73.92. Your remaining account balance for this billing period is CR $100.80.
I understand that CR indicates a credit balance, but since I have already cancelled my service, I cannot apply this credit to the next payment.

Also, because my service is cancelled, I am unable to log into my account.
I am currently back in my home country and cannot visit any store.
Moreover, I have lost the Virgin Plus phone number and cannot use the free phone service from outside Canada.

Given these circumstances, could you please advise me on how to proceed?