Why is the ammonia level so high in my betta tank?

i have a 2.5 gallon tank with a male crowntail betta and 4 ghost shrimp. It has a tetra heater maintaining the temp at 78F and a hagen elite mini filter. The tank is fairly new, i've only had it for a week now but i've had my betta fish for almost a year. I switched him from a 1 gallon tank to the 2.5 gallon without cycling - i know, stupid of me, but i didn't know better at the time - when setting up the new tank, i used the old gravel plus some new gravel which i rinsed until the water ran clean, and i used all the water from the old tank and added some tap water treated with water conditioner. The filter was added a couple days later hoping to culture some bacteria when i found out that i was supposed to allow the tank to cycle. I purchased "Cycle" a product by hagen that is supposed to rapdily cycle the tank and used the first dosage 2 days ago. My fish, shrimp and plants are all healthy and seem to be normal but when i tested the water for ammonia it read pretty high. I've tested the water with 2 different kit and got the same results. Following the testing, i did partial water changes to help reduce the ammonia levels but nothing has helped. What's wrong with my tank? What should i do?