Thanks For getting back to me....

Hi am new to the forum. Just wanted some advice. I am owed a minium of £1135. After receving a letter offering a free will offer of £610. I called them to contend it and they up-ed it to £700. Now I could do with the money asap. But would like to get the full amount. My question is this: If I was to send back there slip agreeing to thier offer as "Partial settlement" Instead of Full. Which it says on the slip. Will it be paid in straight away? Whilst pursuing the rest of amount.