Belfast - Phones in Ireland

Excellent condition S2. Bought on Gumtree belfast but I was ripped off as its blocked by all UK Networks, possibly an unpaid contract phone. Im looking to swap for a southern phone as it will work in the North and my one will work in the south. All the functions of this phone are in full working order, only the IMEI is blocked by UK networks so it wont take a UK SIM but will work outside UK as its not blocked anywhere else. Newry based. Thanks for looking