BD will accept them if you can prove that they have a birth certificate or national ID card issued by GOVERNMENT of Bangladesh. Otherwise, tough luck. You can't simply ring Hasina and expect her to take anyone you call Bangladeshi back. Its likely that she won't even pick up the phone. She has important things to do, you know.What has got to do with deporting illegal Bangladeshis from Pakistan?
If you enter Pakistan legally with proper visa, most welcome otherwise it had to be deported with a black stamp on its passport.
Futher Ummah is as much a responsibility of Bangladeshis as Pakiatanis.