Yep. There is something wrong here. By now, the ammonia should be being converted into nitrites and nitrates....
what kind of filter do you have? - Infact give as many details as you can about the setup. Number of litres in the tank. Type of gravel, temperature, filter type, how fast is the flow, what media are you using in the filter, any plants? What is the lighting like?... There has to be something not quite right that we can help you straighten out.
Are you adding ammonia to cycle the tank?
You seem to be doing a "fish in" cycle which means you can get away with not adding ammonia. They will naturally produce ammonia so no need to add more.
I would personally stop adding the ammonia for a while. Do a water change to reduce the quantity of ammonia and leave it alone for a while.
The fish (in that huge tank) will not produce ammonia too quickly, so the bit that they produce should get the cycle going. Just keep doing water checks like you have been, and change water when the ammonia reading goes above 0.5.
Dont loose faith - it will happen eventually.
No more fish though please. There are plenty there for a fish in cycle. Best not to overwhelm an unhappy system.