[Hampshire] simple contact mgt or call mgt system wanted

Hi

I want a simple system to log support calls for about 20 different cost
centres, preferably with the ability to keep a running balance and raise
monthly cost notes. A simple spreadsheet would do but be a bit clumsy -
key criteria are to have simple lookup of matters discussed to date (to
keep the convo flowing). Ideal would be to have it as a plugin to
thunderbird or evolution!

Any versions of this oft-invented wheel are welcome.

You guessed - I don't want to buy a large commercial solution!

Cheers

Ed