Top Up option allows Dutch-Bangla Bank Rocket customer's to rechrage thier own mobile no or any other mobile no they want. To get this service from Dutch-Bangla Bank Rocket account you just need to dial *322# from any operator except citycell. in case if you are using Citycell mobile phones then just send an empty sms to 16216. Once you dial *322# or send an sms to 16216 you will get the following screen. From the screen select the option 3.