Android problem

Cell is totally formated and reflahed but no results. Scam got physical access and open backdoor. Root checked shows fine log. Anyone here who can help me. Budget is low 20e for 5 cell with same problem, since scam done a lot of damage to me . Secondly I don't want invest more money for something caused by scam, and make them happy. If you dislike scam here is opportunity to fight them. You have to be a hacker obviously. Some of them wanted fix it with keyloger from dark web. I don't want have anything from dark web. Pls bids asap.