Is the free extra minute in the phone programming system permissible or forbidden, and what should I do concerning the past two years if it was forbidden?

If the extra minute added to the call is without the caller's knowledge and consent, then this increase is an illicit gain, partaking of people's wealth unjustly. One must repent from it by ceasing the act, regretting it, and resolving not to return to it. The money must be returned to its rightful owners if possible; otherwise, it should be given as charity on their behalf. If they appear later, give them the choice between accepting the charity or having their money returned. However, if the addition was with the caller's consent, then there is no harm.