First up, try the instruction on this page. I too have a CT100 thermostat and I keep this page updated based on my own thermostats. Also remember that it can take upto 24 hours for the battery to update, even if you press the refresh button it can take time. It’s something to do with the underlying platform and I can’t seem to get any response from the support team on it. But the code works overall.
Second regarding your C-Wire I have the same issue, and I found 2 workaround, first one you can disconnect the G and use it for the C (remember to rewire on both ends) and then short the G and Y at hte thermostat end. This will get your power on the C to the thermostat but you lose fan control (ie the fan comes on when the heat/compressor comes on, but you can individually turn on/off fan, it’s completely automatic). If fan cycling isn’t important this it the easiest and cheapest. Other option is a splitter. Both are summarized here with diagrams:
http://www.hvacproblemsolver.com/new-thermostat.asp