Northern Rock Together - Paying unsecured loan

Hi guys, been lurking aroud for a while and only posted once before - looking for some advice.

I took out a Northern Rock Together mortgage back in 2005 then remortgaged after a 2 year fixed deal in 2007.

Recently bought a new house (7 months ago) and paid off the secured loan but moved the unsecured part of the together mortgage with me to the new property. This is approx £12k over 25 years (same terms as my original mortgage)

Now I'm not blaming anyone here as it's my own fault for not doing more research but when I asked Northern Rock if I could take the unsecured part of the loan with me they said yes - they failed to mention the interest rate would increase by 8% abouve the SVR!

I've now paid 7 months paymets and the balance is still ther same. £12k. I'm now looking to raise the money to pay off the unsecured part of the loan.

I know this is probably a silly question but do you think Northern Rock will accept a slightly reduced payment? ie less than £12k?

The reason I ask is I have managed to raise just over £10k (if the sale of my car goes through) and would like to use this money to pay of this debt as all I'm doing is paying interest.

Anyone tried anything like this before or am I wasting my time?

To add, I have never missed any payments and all my accounts are up to date (no defaults etc)