This is a common procedure that some banks follow when you make a purchase:

  1. When you make a purchase on our website, the purchase is retained by the bank for the amount of time it takes to be processed by StubHub International.
  2. The second charge will stop being retained and will revert back into your account.
     

There are some banks that do this automatically and other banks that make two retentions at first and then go back to normal (showing only one charge).

That's why you may see two charges at first. 
In case the standard time for this has elapsed and the second charge still shows in your account, please contact us