I think as this is before departure you're going to have to "like it or lump it".
the airline have offered you the opportunity to refund or keep your ticket and take compensation, it's unfortunate really but not a huge amount you can do, if you have a high S* status you could see if you could get them to put you on an alternative carrier (I'd guess AC would be the option if you're flying prem) but aside from that you could go down the travel insurance route. Perhaps call them again and see if they will move you to AC ? Occasionally you get different answers when you speak to different people