> How many times?
There is no specific number of times. Repentance helps to remove the sins between a person and G-d, such as one who serves idols. But for one who steals from his fellow, damages him or harms him, his repentance is not effective until he appeases the person he wronged and asks forgiveness from him, and if the person agrees.
One is to ask for forgiveness up to three times. At this point the offended party is required to grant forgiveness or he himself violates a commandment. (Or at least this is what I understand. Feel free to correct me if I'm wrong. Your knowledge is much more systematic than mine.)
Really??