Well after 2 years of having this game with no joy at all, I checked back today and tried the above method... I now have 80g so far =)
The save file was in a different place but I found it when I searched my laptop for "AppData"
All I can say is MS are total wankers for releasing this in the state its in.... why should we need to go around trying all these things??? A proper testing would have found this out!!!
I kept to my word and never bought another GFWL title after I purchased this 2 years ago and I WILL NEVER buy one again after this experience... I'm just glad my 600msp wasn't a total waste and can't believe they're asking £9.99 for this now!!!
61 GAMES COMPLETED XBOXONE (NOT INC DLC)