I presume you are on non-LLU? You could get about 5.5 Meg Sync on ADSL Max. What does your router show as Line/Connection Mode?
You'd probably get less on LLU on such a long line as ADSL2+ will increase your attenuation by about 3 dB.
All "Up To 24 Meg" package means is you could get 24 Meg if you live in your exchange and progressivly less as you wander away from it. At your distance it would be ineffective.
You could only gain from FTTC/FTTH if it were ever offered in your locale.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU BB => 2010: Orange 16 Meg LLU BB