I had 39 Invisalign trays and my teeth were still not straight after them, so my dentist ordered 13 more for my top and 11 for my bottom at no cost. However, currently I am on my last Invisalign refinement tray and both sets of my teeth are still not straight and look like they can use a few more trays. I do not want to retain my teeth as they are now because they are still not straight. Can I order another set of refinements for free to fully correct my teeth?