This has just happened to me too and I'm furious with them! I have got a couple of credit cards that I have always paid off on time, I am on the electoral roll (as I voted in May), I have lived at my current address for 18 years 10 months (all my life!), I had my last bank account for 7 years, had a regular income coming into it for the last 2 1/2 years, have no current credit applications, have never been overdrawn and intended to have my student loan paid into the Halifax account. I am about to start at Cambridge University to read law - what sort of students are they looking for?!
I reckon it is just an excuse, and that Halifax have offered too attractive a deal, have had too much publicity and can't afford to honour their promise of such a high interest-free overdraft limit! I think it is disgraceful, if this is the case, that they are making students feel it is their fault, and I refuse to ever bank with the Halifax Bank of Scotland in my life! I was, in fact, very impressed by the initial helpfulness of the man who dealt with my application in my local branch, and was even tempted, once the student account came through, to transfer my savings over to their bank. Now I will never touch their services again, and I recommend others do the same! In my opinion, they have made a fatal error, and lost many potential graduate customers.