Change of airport - taxi expenses?

Hi - flying Inverness>LHR>Vancouver in the summer. My return LHR>Inverness got cancelled and I’m now returning to Aberdeen. I explained that this makes getting to/from the airport from home a bit of a challenge and was told I’d be able to claim for a taxi home. BUT the agent refused to put that guarantee in writing. Is this going to work, or is this going to cause issues, anyone any idea? Also, I should have clarified with the agent, but didn’t, would you take that as being able to claim for taxi to INV as well as home from ABZ?