Bellafill is a longer-term filler that works on just about everyone but when patients get variable results there are some explanations.
Bellafill results or the results from any filler injection are extremely injector dependent as well as location dependent.  For example, Bellafill results are the best when Bellafill is injected superficially, just under the skin, and not into the deeper layer where many injectors are taught to inject other products like Sculptra and Juvederm.  In addition, areas of the face like the cheek hollows are so called “black holes” for filler, largely because there no bone close to the surface to push the filler up and produce results and a lot of filler is needed to produce good results.
The time to judge your results from any filler injection, including Bellafill, is either immediately after the injection or three to four weeks later.  When your results look good the next day, it means that the swelling from the trauma or injury of the injection have taken over.  When the swelling goes away, and it looks like nothing happened, then either the filler was placed too deep or not enough was used to fully correct your problem.
Here is a video that shows just how much filler is in a 1 cc syringe that may help you understand some of this.