Asking forgiveness from people whom one has hurt

I have a question regarding asking forgiveness from people whom one has hurt or cheated. I did hurt a few people in past, had arguments too. Later when I apologised they said they forgive me and asked me not to contact them ever again. My question is I sometimes get a feeling they might have said so in anger and not meant to forgive me, later on when they might remember any of the things they might again have ill feeling against me. So how do I approach this situation. Are there any specific deeds I can carry out (for eg:making charity and duas in their favour etc) or should I have to contact them (I fear talking to them again might cause more arguments ;both the person's are non-mahrmam) kindly help. Jazak Allahu khair.