I've had this issue with my pearl from at&t and me being a rogers wireless customer, u can do as navilyn stated, or you may contact your provider and have them contact RIM(if your carrier is nice enough) and have them remove the PIN and IMEI from the o2 database this is often times a difficult task as RIM will contact o2 on your behalf just to make sure the device is inactive on their side and not reported stolen as well.