Hi

So I'm travelling YYC-LHR via DFW on Y/WT+. I was looking to UUA to CW for my DFW-LHR segment, and I see that there is availability however I can't do it on MMA and had to call in. When I call in the lady said that as this was booked on my mom's credit card, they have to talk to her and not me. Is this true? If so is there anything I can do? Realistically speaking, she is out of town and can't really call in to BA.

PS: Please don't bash me for having my parents pay for my flights, I am poor lowly medical student as such I have no savings of my own.