Does a divorce issued in writing via WhatsApp, in a state of extreme anger and before consummating the marriage with the wife, take effect? And how can she be returned to the marital bond if the divorce has occurred, considering the differing places of residence of the spouses?

If you pronounced a clear divorce or wrote it with the intention of effecting it, the divorce has occurred. Since you have not consummated the marriage with your wife, her divorce is irrevocable, and you cannot take her back except with a new contract and a new dowry, through her guardian and in the presence of two witnesses. Her guardian can delegate someone to marry her off, or you can delegate someone else in the guardian's country. Delegation by phone is permissible. If you wrote the divorce in a mobile phone message without the intention of effecting it, the divorce does not occur, because writing is an indirect expression (kinayah) by which divorce does not occur without intention.