Yes, actually you could export your private key for that wallet, import it into bitcoind or another web wallet with that function, and you will be able to spend these funds.
Edit: Their response is just a copy-paste. They didn't even bothered to check that the transaction does NOT appear elsewhere on the Bitcoin network, so they DO have control over it.
Sorry...maybe the edit, maybe my brain damage.... i missed this post before!
So, if the transaction dosen't appear in the network, i can try to export the keys? Or would this vanify any future attempt of blockchain to resolve the issue, so better not to mess up and re-contact the support?
Can someone explain me why?
I'm trying to better understand how the network work, i'm still a newbie but so far i understood that trusting ANY site and whining to the support to help is not the best way to manage your bitcoins.