Thank you all for the feedback - rookie mistakes on my part, but got shot down for wholesale changes (Ticket is for Bangkok, so SIN destination change was a no go). Got disconnected but agent had left notes for when I called a second time

YVR-FRA and YYZ-FCO were also shot down by supervisor as the first agent had found a flight and one of the agents (not sure which) opened up 3 seats to catch the original Swiss flight (new 7 am flight has valid connection time as it arrives at 3 something pm, for a 4:50 LX flight). I caved and accepted the change...

In the end, I am merely departing 7 hours later, with no change to arrival to my first stop or my destination. Not the end of the world, but nothing amazing like I was dreaming of