Could this be scar tissue or residual filler?

I've had 2.5 mls of Juvederm injected in my lips over a two year period in the form of three separate injections. The second time round, my top lop was super lumpy and bulbous but I waited it out until it dissolved somewhat and got it corrected. However, it's been a year since the correction and the lumpiness and bulbosity is still there and the shape is very similar. I was informed today by the injector that it feels like tissue. How can I fix this as it is very unnatural looking?