Your phone company is the one that can help you. If you installed Android Device Manager you can perform a remote wipe, but that's before it was reset. If it was already reset you can't reset it again (even if you could, that would not mean deactivation).
If the phone was locked to a certain network, it will be easier for the phone company to deactivate it once the phone is registered to the same network (even under a different number). If it was an unlocked handset (SIM-unlocked) and a different SIM was inserted, chances to do that are getting slimmer.
Your best bet would be to have it reported as stolen at the phone company, stolen IMEI numbers are blacklisted for every phone company access and use.