Ignition coils come with an inbuilt resistance or external resistance.. (white in colour). The resistance gets extensively heat up, this is normal. May be coil you are using has internal resistance and the heat you are getting is from that. Then, at times coils are oil filled to keep them cool .. the coil circuits remains dipped in oil for better conductivity, less sparking and cooling. May be you fitted coil at some odd angle and its circuit is not fully dipped in oil, causing it to get heated. Lastly there is no need to replace a coil with an expensive one its function is quite simple and as long as the spark is good you may next time replace it with a std suzuki mehran coil.
Do get it checked from an electrician .. though it seems ok to me .. try a normal electrician this time with good reputation, instead of the expensive company repairs.
Best of luck