Hello I have a question about what can be done for a relative who got a visitor visa and arrived in the U.S but is being deported for credit issues

There is really not enough information to assess what can be done. Credit issues are typically not the concern of CBP. That being said, if your relative had a social security number that has been active, CBP may believe he has been in the country in violation of his prior term of admission. You should consider consulting an attorney about what can be done if your relative is still in the country or to bring him back.