Firstly your anonymous and criticising others who help. You said you have just joined, but form an opinion based upon what and you hide. Really, it's people like you that are the frustration.
Tell them your reporting them to the Police and Immigration since they won't honour what they sold you to obtain the Visa, so they are in essence also scamming the Royal Embassy as well
Immigration means coming into a country from another country, if your travelling within that country then its domestic travel, however, you will still need to present your passport as form of ID and it will feel very much the same, until you arrive at the destination airport where you won't get a stamp in. You also don't get a stamp out at departures.
I've done mine, passport, visa and TM30 handed them over, they completed everything and stapled the report in my passport, dead easy, I was expecting to fill forms out.