Non-paying buyer on eBay. HELP!?

Had a friends designer dress for sale. Lady offered me �80 for it. I accepted. She pays using paypal and I send her the dress - the usual procedure. Few days later paypal reversed the money. This had never happened to me before, so I contacted her. She said she "thought" her paypal account had been closed due to her changing bank accounts. I was cool, didn't want any kind of dispute, so told her I'd give her a couple of weeks to sort it out. Two weeks later still nothing. Contacted her again. This time she wants to pay with online banking or cheque. I email her the details to write a cheque and which address to send it to. Ten (or so) days later no cheque. I contacted her again. She claims she sent the cheque almost a week ago. I send her another email requesting her to send another cheque. She didn't reply and I haven't heard a thing from her since. The whole time she's been playing games. I've been waiting 2 months now and it's increasingly becoming clear that she has no intention of paying, and possibly never had any intention in the first place. Paypal haven't done a thing to help - even though I provided them with all the necessary proof - and eBay just tell me to claim back my final value fee. They haven't even suspended her account! So, what's my next step? Should I just accept that every once in a while this is going to happen and move on. Or, well......what exactly? The Police? After all this is a premeditated theft tantamount to burglary. Right? Some advice would be much appreciated. Thanks!