After a listing is restored, it takes up to 2 weeks for the listing to fully recover. This includes recovering all your ranks as well as all your reviews. As part of the restoration process, your reviews are audited to see if any were frauglant. If fake or fraudulent reviews are found, Google will remove them.
There have been times where Google’s system had glitches with restoring reviews. If you know you had 100 legitimate reviews, tell Google you know you had 100 reviews and that its has to be a glitch on the back end. Keep pressing the matter until Google escalates the issue. With that being said, be honest with yourself. If you bought the reviews or they just overall fake reviews, asking Google over and over will lead to a dead end.