Anyone affected by this should raise a formal complaint with Santander and get a complaint ID number.
Also, I checked with the Financial Services Authority and this does seem to be within their remit.
The complaint form is on their website at:
http://www.fsa.gov.uk/pages/doing/regulated/promo/report/form.shtmlThe more complaints they receive, the more likely that this may be prevented.
Don't leave it to other people.
Although £7.50 a month isn't huge, the principle is that they are trying to break the promise that got them so much business in the first place. If they get away with this, the charges will soon escalate.
Until a few months ago, Santander only charged a tiny amount on personal account overdrafts. Then Halifax started charging £1 a day whatever the overdrawn amount. It didn't take long for Santander to follow. They started with 50p per day and limited it to 15 (I think) days in any charging month. Total maximum of £7.50 a month. Once they realised they could get away with it, the charge went up to £1 a day with a 20 day ceiling - a maximum monthly charge of £20. Trust me, if these vermin get away with this initial break of promise, higher charges will follow.