If what you actually need from your employer is a promotion or pay rise, do not threaten them with resignation. Instead ask for it outrightly.
Have a discussion with the HR and back your request with cogent reasons and documents such as your employment contract to show that you are due for a raise.
You may also include evidence that you have passed the required courses and qualifying assignments either within or outside the organisation.
If you use the resignation scope while you are not really serious about resigning, you might be setting yourself up for some career heartbreak.
This is because you may eventually get the raise you need in a counter-offer from your employer who will no longer trust you. And it is just a matter of time before you are shown the door.