The Problem that you're having if i understand what you've said you've done is if the rad was drained and all you did was put coolant in the overflow can that olny fills the can.
If you want to fill the Rad you need to open the Rad cap and put the coolant in there once it's full turn the car one once the Thermistat opens you see all the coolant drain out (so to speak) when that happens top off the rad again. keep doing that till you can't put any more in.
and if you get no heat from your heater after you've done this it means you have an air pocet in you heater core and you'll need to remove the heater hose frome the heater core and fill it manually.
Hope this helps you out