Most likely yellowjackets.

If so, the colony will die at the end of the year. So, if you can avoid that area until then, the "problem" will take care of itself.

Another option for yellowjackets is to get a can of the long-distance spray for yellowjackets, then use according to directions.

If you do, understand it's important to apply it at night, directly to the entrance hole, and use the entire can, ending by plugging the hole.

Hi...
They're most definately not yellowjackets or your normal everyday hornet. I'm familiar with those and honeybees, and Bumblebees as well.
I've never seen this type of bee until the day of the attack. I finally killed them late in the evening by finding the hole again with a flashlight while riding my lawnmower for a quick getaway, then I doused the hole with a gallon of gasoline.

I am apparently allergic to wasp stings having gone to the hospital with severe swelling on my arm. But I am not afraid of them because in the construction business I encounter alot of them and I know that they won't bother you if you don't either disturb thier nest, swat at them or accidentally bump against them. What disturbs me about the post is the gallon of gasoline. Gasoline is highly toxic to humans as well as animals and plants of all kinds, and most of our drinking water comes from the ground. Next time I would either mark the area to warn people away or spray the nest at night with wasp & hornet killer. be sure to be upwind of the nest as you don't want to breath the stuff. It sounds like the stings were pretty bad so I hope you never encounter them again. Stay well. Alan Parker

If you can find a body of the wasp/bee take it to your local extension office for identification. Another possibility is a small nest of africanized bees.

I had a nest of ground dwelling yellow jackets in one of my flower beds. I left them even after they chased me until they started being agressive when I went to the mailbox. I found that you could kill them by sprinkling boric acid powder around the hole at night. Be certain to do so on a moonless night and turn out light after sprinkling. Do not run toward any light they can follow your outline. If you can not find boric acid powder in the optical part of your drugstore look for the roach killer containing it. The one in this area used to be called Roach Rid. Be aware that boric acid will kill the good insects so use very carefully.

Dousing the soil around the entry you found probably did little, in reality, except poison the soil and the "bees" most likely had another entry/exit they could use and are using. Since bees die after stinging you, few will although the africanized bees may well do that. You do need to properly identify what is there so the appropriate course of action can be suggested.
Why was your Extension Service office not helpful?

Take a look at a tarantula hawk, I just encountered one and it sounds like you experienced.