in 1st place, there was no Marriage so this case will not stand.
2ndly Police cann`t arrest you, see the direction of Delhi Police.you can ask our Delhi members for this or search on Internet. Delhi helpline numbers can be found here http://mynation.net/contact-us/
Give in writting to Police about her statement, and tell them, if they do not stop harassing you, you will meet Higher Authority of Police.
no need to pay anything,whatever they spent.if they still threaten, there are limitation to spend on marriage,as you did`t asked for it.
and at lastly, you can go for HC to quash FIR,
refer some of the judgements
and many of the other judgments Available here http://mynation.net/docs/sitemap/