Thank you for contacting Avangate.
We apologize for the discomfort created by our verification process. This process is intended only to prevent unauthorized credit card use.
All the transactions are made in a very well secured environment. We are asking for more information only in special cases where the identity of the person that places an order is uncertain as being the credit card holder.
When uploading the copy of the bank statement you can mark as unavailable, or "hide" information like: account balance, recent purchases (except the one towards Avangate if available), part of the card number connected to the account (leave open just the first 4 digits and last for digits of the card).
And also leave in sight your account information like: Full name, home address, phone number(s) etc.