How are you getting on? Have you approached the local councillors, MSPs and MPs? What about the organisation called Play Scotland? Letters to local newspapers could help and you could contact the regional TV news. Maybe you've already done some of these....?
I don't want to bore you with the importance of play-parks for child development, you will know all the details. On a completely voluntary basis I along with another Mum of young kids have taken on the project to replace our local play-park. It's in an awful state and we call it the "don't run park" as that's what all Mums, Dads and carers yell to their kids. Without fail someone will come away from the park having fallen or slipped on the crumbling gravel. Long story short we need any help we can get to share our message. All the details about our project can be found on our Facebook page /RoseanglePlayParkDundee. We are completely genuine and would appreciate any help or likes ;)