Reuse of Consent

We have customers who are receiving electronic statements on one account (have already provided agreement online that they understand and consent to receiving electronic statements) and then come in at a later date to open a second or third account. May we use the previous consent since the customer is the same, computer being used to access the account is the same and the email address is the same for notification purposes? We have had customers consent again when they open the second and third account and are now receiving lot of negative feedback from the customer. Most importantly they do not understand why we do not automatically set them up for e-statements on their new account since we know them and know they can receive and read our electronic statements.