radiya asked 4 years ago

salam wa alaykum 
I stole some money from a friend years ago and I feel very bad. having confronted her through a third party and admitting what I have done. i told the third party i have no problem giving it back or I asked for forgiveness. she said she dosent want it back and she wont forgive me. she then called the third party a couple of days after and said she needs time to think about it. however a year has gone by so I asked again today and she said how much money did I take I said I do not remember but I think it was just over 300 pounds so I dont mind paying 400 and giving 500 extra just to say sorry. her reply was pay me 500 pounds and I will forgive you. I then said ok even though the amount was not what I took I agreed but told her I need it writing for proof she replied and said pay first then I will forgive you. this girl is not a muslim so even though I explained to her about islam and the importance of forgiveness sand there is ways of doing things she did not care. so my question is please could you tell me what I need to do as I’m not sure how much I took and really need her forgiveness as I’m sure I’m islam if you take something taht dosent belong to you you either have to give it back or ask forgiveness. so do I give her what she asks I  hope she will forgive me or please could you advise me how you see this situation. any advice would be appreciated.
thank you