Obtain a confirmed ID.

Any chance of capturing one or more and posting their pictures?

yes

These are just like tiny mosquitos.

Sorry, the image is too fuzzy to ID.

Perhaps the source isn't the potting mix.

Try some nematodes that target fungus gnats specifically, maybe?

Azamax sold at Ebay. Strong strong neem oil. It will work.

Hi Abid did you manage to resolve your issue?

How many plants do you have? You could isolate everything with some net/mesh and see if you still have gnats flying around. I found the fastest method to be simply tipping out all plants, throwing all soil, disinfecting everything and repot with fresh sterile potting soil. I would throw away any infected plants that you don't really care for, it also declutters your collection and makes space for things you like more :)

for some reason, i didn't find gnatrol very useful. Sticky sticks worked well. So now I prefer to put sticky sticks and water less frequently to get rid of them.

I have been battling these for over 6 months. Figured out it was really drain flies. I started out by clearing the scum out of the sink drain pipes and used Zep Drain Care to kill out the eggs and food source and used PIC Window Fly Traps (these are NOT sticky traps) along with applecider vinegar traps and it worked. Have not seen them in over 3 months. Try it.

Do you have fruit sitting out all the time?

Fungus gnats can be eradicated, as can any insect pest. However, what that pest might be needs to be properly identified and then the proper control measures need to be put in place. If what you have/had are Fungus Gnats then the Gnatrol (Bacillus thuringeinsis - Israelensis) that would have controlled them, if it did not then the insect is not Fungus Gnats.

Many times simply being more careful with watering those potted plants is the simplest and best method of control. After completing the Mater Gardener, and Advanced Master Gardener classes and while working at our local Extension office advising people about growing plants the major problem we saw was simply over watering.

Perhaps this article about Fungus Gnats might be helpful.

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7448.html