My guess is you didn't use enough to get a large enough quantity of the mound, so try doing this mix again in five gallon
1 cup molasses
1 cup compost tea
1 cup cornmeal
1 oz. Orange TKO or 1 cup orange oil
to each gallon of water.
I used this amount to kill off a huge fire ant mound underneath the walkway at my daughter's school that a man told me had been there for 10 years. I took a 5 gallon bucket, a big funnel and used a 1 inch pvc pipe about 10 feet long, pushed it into the mound under the cement as much as I could, and poured until it was gone. YOu need to get the mixture into as many tunnels in the mound as possible and there are a ton of them!
I had treated it with compost/molasses/orange oil once before and knocked them down but for some reason adding the cornmeal to the second application knocked them out permanently. There are probably a load of queens in there so it may take two hits but don't give up!
Oh yes, and get some beneficial nematodes into the area either before or after you do this application. What the mix doesn't get, they will!