Understanding digitally signed agreements with ABSA?

[Milano]

Looking at implementing a digital signature system in one of our departments. When updating your personal details related to your bank account inside a branch, ABSA requires you to sign on a digital signature pad for agreement while providing both thumb-prints for security. I need help understanding the signature part of the transaction. The operator in the branch changes your bank details on the operator's terminal which is only visible to the operator. The client then signs digitally on a digital signature pad. No hard-copy is provided. Is it correct to assume that the client's digital signature represents the client's acceptance that the updated personal details provided by the client verbally do in fact match those entered by the operator? How is that legally accepted as an agreement if the client is unable to view the documented changed?