Something else that seems to have been missed: the OP's original request to Kobo was indeed to cancel the second gift card--though she wanted it done without her mother knowing.
Kobo couldn't do it without her mother knowing, but they did go ahead and cancel, because that was indeed the only specific instruction they had from the OP--the rest of it seems to be demands for things they could not do, like give her the second card for free.
Can't believe we're still talking about this!
Edit: Here's the quote from the OP's first message:
So I immediately got on the phone with their toll free number and tried to explain to the person on the other end was it possible to cancel one without my mom knowing.