>>395 (OP)
Credit repair companies are a scam. If you owe a small amount just pay it off and be done with it.
For larger amounts that you're unable to pay, for example a large credit card debt, the credit card company will attempt to contact you until the minimum payment is 90 days past due. At that point they'll most likely sell the debt to an outside collection company who will aggressively attempt to contact you via phone and mail. If you respond to their letters or pick up the phone when they call that will be considered as a commitment to pay.
However, if they're unable to make contact with you then there's not much that they can do except maybe resell the debt to another collection agency. After 7 years nobody will be legally able to sue you (unless the laws change of course). The worst that will happen is the company/bank that gave you the original loan will send you letters offering to give you another account after you've paid them a large amount of money every month for the next 5-7 years.
As long as you don't answer their phone calls or reply to their letters there's practically nothing that anyone can do to you after 7 years. (This assumes that you haven't taken 6 or 7 figures from them, in which case they'll probably hire private investigators to find you and then press charges.) If after 7 years an old debt appears on your credit report you can request that it be removed. You may have difficulty getting a loan with old debts on your report but once they're gone it'll be as if nothing had ever happened.
This is NOT legal or financial advice. Play at your own risk.