Why after 3 ml of hyaluronic acid do I not see any results?

As a very vague generalized question without enough important details (what exact fillers used?, are you sure 1 syringe each session?, was it an injecting MD?,post photos.) my response shall be also generalized. Maybe you received diluted filler?, Maybe you did not have FDA approved fillers?, Best to seek a copy of your medical records and the stickers from each of the 3 fillers you had, all FDA approved fillers has a product sticker in their boxes. Than seek an expert filler MD to see you in person. I have seen your exact situation more and more frequently. Because either you did not use an expert injecting MD or you desired to use an inexpensive route.