Apparently you can re-contract with Aquiss after year 3 and get any discounts .
so
year 1 - 12 month contract - and any discount
year 2 - rolling monthly
year 3 - 12 month contract and any discount.
That's not quite right - the timeline would look like this...
year 1 - 12 month contract - with discount
year 2 - rolling monthly
year 3 - rolling contract
year 4 - recontracted for 12 months with discount