Hi Dellbell,
Fat in the belly is usually the last to go.
I'm frustrated too, been dieting for 4 weeks and went from 89kg to 85kg, but am still storing a little bit of fat in the belly area.
Abdominal exercises won't target belly fat, as you can't spot reduce fat from specific areas of your body.
Best you can do is improve your diet a little and keep going.
Your fat loss so far has been good, you might have to reduce calories a little to keep losing the fat.
Use the dumbbells whenever you can, as increasing muscle mass will help burn calories faster.
Good Luck