You are experiencing the frustration we often have with inaccurate info on Trulia (and other listing sites). When there's an error... even a crucial one like yours... it's difficult to get it fixed. There's no one you can call. You just have to send an e-mail and hope someone at Trulia will get to it.
My frustrations with Trulia are usually regarding the photos, prices, and the limited amount of editing I am allowed to do. I don't know that I have ever seen an active listing showing up as sold before. Yours is definitely still showing up as "active" on the MLS.
I do like their site and the way they present the properties, and they don't have as many errors as Zillow.
Good luck to you!