For educational purpose below is my port of entry experience from departure to destination

Nigeria: I booked a Turkish flight 330 pack my bag on the D day to the muritala airport did check in procedures when tru immigration NDLEA and custom check as usual oga anything for us and I said am sorry I don't give bribe but not never break travel laws show hotel flight work I'd etc and the said safe trip fast forward to uk entry

U.K. :Port of entry came down from plan free wifi long queue and EU& British passport holders separated no check just scan your passport on a machine scanner and pass

Other country passport holders are made to queue for immigration check now it's my turn

Me:good morning sir
C.O: good morning passport and ticket
Co : why are you in the uk
Me: traning handed invite
Co: check and and ask me to wait he left like 10mins
Co: your traning has past was done last month and next one is in October
Me: yes I know visa was not issued in time and I complain to organizer and the gave me option to add 500pounds for a one on one vip traning
Co: receipt of payment
Me: gave him
Co : accommodation
Me : gave him hotel confirmation
CO: have your paid
Me: lied yes made deposit
Co: hold he called hotel and they said no payment was made
Co: sir hotel said u did not pay how come who is lying
Me

Me: I regain confidence yes they are right cos I ordered my bank to hold payment till I check in
Co: oh ok can I see your bank statement what's your balance
Me: yes why not took him to atm show him my balance was 7000pounds
Co: ok do you do drugs and can I see work I'd
Me: I beg your pardon I am one of director in my company he check my id search all my luggage and said am sorry but I need to be sure cos my supervisor want you to be sent back and I said why I don't know but I like you give me your have your passport have a nice stay on London and make sure you leave at the end of activities and I said thanks. God at work right? Share yours

I think confidence is the KEY word there.

You didn't fidget at all

Professional...businesslike. .. to the point... but the CO lied to you!... his supervisor wants to send you back and he decides not to?....he is the one that was fishing for something to send you back!

Confidence is paramount, and you were so thoughtful of your prompt response and were funny. How can he ask if you do drugs even if it were a drug baron he would have lied instead and the part of the hotel.. You really sound smart there sir.

Originalsly:
Professional...businesslike. .. to the point... but the CO lied to you!... his supervisor wants to send you back and he decides not to?....he is the one that was fishing for something to send you back!

You can say that again

sobastical:
Confidence is paramount, and you were so thoughtful of your prompt response and were funny. How can he ask if you do drugs even if it were a drug baron he would have lied instead and the part of the hotel.. You really sound smart there sir.

Thanks for your comment

fiftynaira:
I think confidence is the KEY word there.

You didn't fidget at all

You got it but bro to be Honest it's not easy it's like am on a hot sit lol