Do you mean the amount displayed on the collection page isn't the amount you're getting, or it's just falling down constantly?
At your infrastructure level, you should be aiming for more than a 14k a day profit. Buy 15 technology, delete the clinics and hospital and buy 2 more banks and fill the rest with stadiums and you should see a significant increase in your collections. 5 banks and 5 stadiums are the best way to go after you have your harbour, foreign ministry and factories.