Surprise offer for Grameenphone Customers on 20th birthday! Grameenphone has brought a special offer to celebrate their 20 years, Where customers can enjoy different types of offer by dialing *2020#.Just dial *2020# to know your offer.The Campaign will run from 27-March-2017 to 02-April-2017 Gp 20 Years Celebration Offer: – All Grameenphone Pre-Paid, Postpaid