Re-entry ban?

[grrl22]

Hi there--first-time poster with a question re: re-entry bans.

I was recently refused entry to the UK as a visitor (US citizen seeking normal, 6-month visitor visa upon arrival at a UK airport). It's a long story, but the gist is that this was the result of a genuine mistake. I thought I could apply for a longer-term (student or spouse--I am married to a UK citizen and am also enrolled to begin an MA course at a prestigious university in the UK in October) visa in-country, but learned that this is not possible. Had I been let in, I of course very quickly would've discovered this mistake and would have flown home to the US to make my application there. I was honest with the immigration officials about everything, and this was orally acknowledged. I received a letter stating why I was refused entry, and this did not include anything about any form of deception of lying on my part, and it does not contain any information about a re-entry ban. I was transported on the next flight back to France, where I had been on holiday, by the airline--there was no option given as to whom would pay for this flight, and so I am a little confused by the "at your own expense vs. at the expense of the UKBA" information I've found in the UK law...I was told this was at the expense of the airline. I am now returning to the US and would still like to attempt to make my student visa application in the US, but I am worried as to whether or not I stand a chance with it.

In short, I am now confused as to whether or not I am subject to the 1-year re-entry ban. When asked, one of the immigration officials told me that this refused entry would not affect my future visa applications. However, I am uncertain about the validity of this statement--obviously I will still need to disclose this information as part of future visa applications and include a detailed letter explaining what happened. Nothing about a ban was mentioned orally or in writing, and in fact, I didn't know such a ban existing until after I was released and did research online. So if this ban applies to me, would this have been mentioned in the letter/documents I received? I am extremely concerned about this affecting my plans to study in the UK this autumn, and am semi-resigned to the fact that this stupid mistake on my part may have cost me my study plans.