Expanded polystyrene can be recycled at South Access Road Reuse and Recycling Centre. Dixons Carphone (owner of Currys PC World) also allow customers to return expanded polystyrene for recycling. Read more on the Dixons Carphone website.
Please note that expanded polystyrene is the kind of sturdy packaging material that is used to protect products such as large electrical appliances. It is not the same as the type of polystyrene used to make takeaway containers.