As dermatologists and plastic surgeons, we do our best to ensure that the scarring following mole removal is the least noticeable, the faintest, and the best shape so as to bring optimal cosmesis to the area. Due to some factors beyond our control, whether that be a local infection or inherited healing ability, these scars don't always look great. It sounds like your “hole” is one of those instances, where the cosmetic outcome is not ideal.
You have options to treat this hole in your cheek. We can resurface the scar with ablative lasers and chemical peels, but perhaps the most successful option, depending upon the size of the scar on your cheek, is removal of the scarred tissue with re-suturing. Recreation of that scar in a controlled setting can result in vastly improved cosmesis. This second option may seem severe, but it oftentimes can undo 10 years of bad cosmesis in one session, in which we recreate the scar in a preferred fashion.