So? There were so many Tamils in Sri Lanka after the boundaries were "set" post independence....that came from India during British Raj. India took them all back in 1964. Sri Lanka did not give them citizenship and there were negotiations and a final agreement was reached.
https://en.wikipedia.org/wiki/Sirima–Shastri_Pact
Similarly, Burma does not recognise Rohingya as its citizens and these people originate from Chittagong...the resolution is quite simple here. What is preventing from Bangladesh negotiating a similar agreement with Myanmar? You want India and/or China to broker one for you? Then say something to them rather than quibbling about it to the UN and other useless organisations.
BTW you are welcome to do "covert" actions against Myanmar....you just wont enjoy the consequences one bit I can tell you that. Myanmar wont cry or whine, they take firm decisive action. I only see BD crying and whining here.