Reading today that City aren't worried and expect the ban to be overturned. If their appeal with CAS fails, they plan on taking their appeal higher up, the Swiss Federal Supreme court for example.
In other words, take it further up until it gets revoked. Apparently, City are far richer than Uefa and can afford better lawyers, quite how this makes it certain to fall in city's favour is beyond me.
If I murder someone and there's shit loads of evidence against me, paying billions to a law team is hardly going to guarantee my let off is it!?