Forgiveness

How many times must a person apologise to me before I forgive him? I guess it depends if he was really repentant. But what does the bible say about this?

Matthew 18:21 (New International Version)

The Parable of the Unmerciful Servant

21Then Peter came to Jesus and asked, "Lord, how many times shall I forgive my brother when he sins against me? Up to seven times?"

Ok, seven.... so I haven't used up my quota yet...

When ever I think about forgiveness, I think about the guy who cheated us of more than 20K of our hard earned money when he ran away with our payment for the renovation of our flat. He was a friend, and that was probably why it was tougher to forgive him cos' I trusted him like a brother. And till this day, he still refuse to admit to his mistake even though all the evidence were against him. He claimed that the money given to him were deposited into his friend's bank account cos' he was going through a divorce at that time and thus if he deposited the money into his own bank account, his wife will be entitled to a portion of it. And then the money conveniently disappears and he says that his friend has withdrawn it without his knowledge. He was unable to recover the money because his "friend" has gambled it away. We then found out that he was already an undischarged bankrupt when he tricked us into using his company fo the renovation project. The reciepts that were issued to us were fraudulent because his company had closed down a year ago. Tell me again that this is not cheating??
I might have chosen to forgive him and work out a way for him to pay me back slowly if he had simply admitted to his folly and asked for forgiveness. Too bad for him but this is now a police case and I have no intention of simply letting it go.

To the people I have sinned against, I'm truly sorry if I've caused you any hurt. Especially those close to me. certainly i did not wake up one day and decided to plot against you so that I may see you suffer. I can understand if you may be more wary of me if I ask you to trust me again. It's simple, once bitten twice shy, twice bitten never try. However, do give me the opportunity of being innocent until proven guilty. It's the same with the guy who cheated me. I cannot do anything until the court proves him guilty.

This is my simple request.