Inmy humble opinion If there isn't a affiliate office that can fill the prescription for her maybe she can go to Costco or something like that. I would probably cheerfully say, I wish i could help but I have already made plans and I am unable to help, could you possibly try Costco or another office to get them.
I personally wouldn't go the route you had planned as it removes from Love Bank (SAA book) and If your still wanting the marriage at this point further damage would need to be controlled. I am in no means saying you should be a door mat at her beckon call either. I am a firm believer there is always a way to answer even if the answer needs to be firm. Were you able to get SAA yet? It explains so much!
Anyways that 's just my 2cents may not be worth much.
I think you should wait 3-4 hours (so not "at her beckon call"), and then text back a modified version of T2L's suggestion: "Sorry, I just got this. Did you get this taken care of? I wish i could help but I have already made plans and I am unable to help. You might want to try Costco or another office to get them."
