Upvote:15
She only wants to visit for a short period but I called a company called [random company name goes here] and they said she would most likely not be able to come into the country without the visa?
"...most likely..." get removed again is correct. When somebody gets removed from port the odds are pretty good that they will need an entry clearance to get back in. This is not a requirement and it is not always the case, and sometimes people show up again and get admitted without an entry clearance. But most of the time they get removed again.
It's common for gf's visiting bf's in the UK to engage the Immigration Officer in a 'cat-and-mouse game' about the true nature of their visit. In fact we had one four days ago (Refused 'Leave to Enter' at Gatwick Airport UK (and subsequently removed)) and another one (Refused leave to enter uk) and another one (Getting refused entry and removed at Heathrow, X in passport), and despite the letter saying she was compliant etc, they will have also recorded that she did not play it straight up and that gets them annoyed. That increases the likelihood of a removal from port.
How can it be that she can't even visit, even though she has a return flight and fully intends to return home?
This is because it is massively difficult to unwind a situation where the person has not been forthcoming with an Immigration Officer. Also, as pointed out in the comments, the presence of a return ticket (although required at a port of entry) does not indicate an intent to obey the rules, and her intentions are irrelevant because they stop trusting a person when they have been caught playing 'cat-and-mouse'.
Can someone please advise me on what to do please?
Two options are open...
Alternatively you can try one of the family formation routes, please use Expats for questions about those visas.
Note: the linked questions/answers in the archives can be valuable reading for you. I was planning to mark your question as a duplicate, but there are enough differences to make it unique. There's more reading at https://travel.stackexchange.com/questions/tagged/removal
Note: removals from port do not generally attract a ban, but deception in a visa application will attract a 10 year ban. Your gf should make a full disclosure about her relationship, how it started, what happened throughout the course of it and so on.
Note: There is a forum at UK Yankee especially dedicated to US/UK couples who are in a long distance relationship. You can go there and start a thread that links to this answer and get some reactions from the crowd there. Removal/Refusal of the US person (usually female) is a known commodity and there are some that have shared your woes.