Hi have flight PSP to YEG for inlaws. MIL needs aisle seating as she has a hard time walking and standing up. I requested wheelchair service and handicap seating upon booking and did not want to pay extra for preassigned seating. They assigned seats 4A and 4B but refuse to move to 4C (online check in shows seat occupied, phone agent Lisa from Calgary says empty but cannot as only Airport can assign seat. Lisa from Calgary apparently has no supervisor comes and goes as she please, has no last name, nor a Westjet ID.

Am I out of line requesting aisle seating without wanting to pay for it?

What are my options?