It's gonna cost more than that...
Thanks to their shenanigans I noticed that my savings account with them was paying 0.05% interest. I went in to complain, on a day their internal systems were down. They said they could do nothing and asked me to come back another day. When I did, I was told I have to book an appointment with someone and so would have to come back again (no one told me this the first time). I finally arrived on the appointed day and, after a mix-up where I was left waiting for the wrong person finally saw someone. They explained that they could, as a special favour, up my interest to 0.4%.
Meanwhile banks are offering 3 or 4% on current accounts (up to the first £1k or so at least). so it seems sensible to open a few of them and spread things around, or at the very least ditch TSB for savings.
TSB seem to be relying on the fact that interest rates are so low that the difference in return is barely worth the effort - but they have been such a bunch of d**ks that I'm now moving out of spite.