You should read the information at the following site.
https://www.thebalance.com/how-will-debt-settlement-affect-my-credit-score-960540
Note that debt settlements will remain on your report for several years and there is not much you can do to ameliorate that situation beyond just waiting until they fall off (expire). If the amount is erroneous, you can file a dispute with the credit agencies.
See https://www.annualcreditreport.com/filingADispute.action
