Wednesday 3 May 2006 3.07pm
There may also be penalties (as well as the interest), which they may have charged first (and so not reduced the debt by as much as you thought they have done).
I think that what I would do is to keep paying the instalments for the time being, keep all my records of payment, and write to HMRC and ask them to explain their statement. They may have got it wrong.
...if you press it, they will come.