HSBC refused to update my account status after paying them!

I lost some of my property because HSBC, it happened that I fall 180 days behind. On that time I had lost my job and I could not afford to pay my bills and had no choice so the bank took away my car and other stuff as collateral. I asked my close friends and relatives to help me with the financial crisis I'm going into. Being able to somehow go back, have a job, HSBC are fraudsters, I got a letter in the mail willing to settle $ 500 and we both agree to this amount I sent payment of $500 and now they refused to update my credit report to say I settled for less than owed. My account is stuck with a charge off status after I settled it, I already payed for it! Why can’t they update my account to its true status? I have everything in righting and they refuse to honor it.  I'm going to dispute this! This is worsening my life.