Any cellular whizzes out there ?

Take it to the nearest shop of your service provider and have it re-set. This isn't a "cracked" phone, right? So, they won't have any problem with restoring it...right? Otherwise....enjoy your new career in broadcasting!

I would bring a lawsuit against that person

Don't restore the cell phone. Use it as evidence against him

Hey what fun you can have.

Call someone and discuss how his boss really likes people who shake hands a lot.

Phone a friend and discuss a $1,000 bet on a horse race that you know to be "fixed".

Make him some coffee and when he's drunk it call a friend to discuss a recent trip to the STD clinic.

Google found..

4.4 Retrieving the Key from the SIM The security of the whole GSM security model is based on the secret Ki. If this key is compromised the whole account is compromised. Once the attacker is able to retrieve the Ki, he can not only listen to the subscribers calls, but also place calls billed to the original subscriber's account, because he can now impersonate the legitimate subscriber. The GSM network has trip wires for this: If two phones with the same ID are powered at the same time, the GSM network notices this, makes a location query for the phones, notices that the 'same' phone is in two different locations at the same time, and closes the account, thus preventing the attacker and the legitimate subscriber from placing calls [2]. But this is not relevant if the attacker is only interested in listening to the calls of the subscriber, as is assumed in this paper. In this case, the attacker can stay passive and just listen to the call, thus staying invisible to the GSM network.

Sorry that's GSM.

Put that phone in a crusher/shredder and disavow yourself from that "guy" forever!