Unable to delete broken instance in CAL

Hello,

I tried to deploy an instance (data Intelligence) but for problems on the infrastructure the provisioning job has failed. Unfortunately, as of now I cannot retry to deployment again for the same solution, because I'm unable to delete the previous one. The strange thing is that my colleague tried to deploy the solution (that one that resulted in error), but isn't visible in its "instances"; I see it but I cannot delete it. I tried to delete the user that launched the provision but the system tells me that I have to first delete the solution...so I'm in a deadlock.

Can someone help me?

Roberto