In your trigger if block you are check if case is canceled.

if(c.Status == 'Cancelled')

and in your test class you are setting it as 9-Cancelled and as Cancelled is not equal to 9-Cancelled , its not entering the block.

You can fix it by fixing the case status in test class.

    test.startTest();
    c.Status= 'Cancelled';
    update c;
    test.stopTest()

In your trigger if block ,you are checking if case is canceled.

if(c.Status == 'Cancelled')

and in your test class you are setting it as 9-Cancelled and as Cancelled is not equal to 9-Cancelled , its not entering the block.

You can fix it by fixing the case status in test class.

    test.startTest();
    c.Status= 'Cancelled';
    update c;
    test.stopTest()