Where is dldlc located? dlc, First Floor, Plaza One, Ironmasters Way, Telford, TF3 4NT. Hillesden Securities Limited trading as dlc is an Appointed Representative of Wescot Credit Services Limited which is authorised and regulated by the Financial Conduct Authority with firm reference number 688858.How to contact duquesne light company customer service? Current Balance: Additional Accounts Please enable Javascript for the site to work properly. Contact Home> Contact Mail a Payment Duquesne Light Company PO Box 371324 Pittsburgh, PA 15250-7324 General Comments Duquesne Light Company 411 Seventh Avenue (6-1) Pittsburgh, PA 15219 Customer Service 412-393-7100(residential)