What should I do to get my children back and see them after my wife's family took them, exploiting an old divorce certificate, given my inability to resort to official channels?

If a divorced wife who has been divorced once or twice, and has been consummated with, is within her waiting period (iddah (definition)), she is legally your wife, whether she accepts or not, according to the verse: "And their husbands have more right to take them back." Her family should advise her to return and not persist in disobedience. To resolve the problem, try to persuade your wife to return, and seek mediation from someone who is respected by her and her family. If that does not succeed, take the matter to a judge. We advise you to be patient with this tribulation, as it expiates sins, and beware of not being content with divine decree. You must also repay your debts to their owners whenever you are able, and it is not permissible to hide from them except in cases of hardship.