(d) Service of Summons Upon Individuals. Service upon an individual from whom a waiver has not been obtained and filed, other than those specified in paragraphs (e), (f) and (g) of this Rule 4.1, shall be effected by delivering a copy of the summons and of the pleading to that individual personally or by leaving copies thereof at that individual's dwelling house or usual place of abode with some person of suitable age and discretion then residing therein or by delivering a copy of the summons and of the pleading to an agent authorized by appointment or by law to receive service of process.Arizona Rules of Civil Procedure:
http://www.served.com/az.aspArizona Revised Statutes:
http://www.azleg.gov/ArizonaRevisedStatutes.aspTitle 12, The Courts and Civil Proceedings:
http://www.azleg.state.az.us/ArizonaRevisedStatutes.asp?Title=12Notice no requirement that the minor be over a certain age, just "Suitable age and discretion", which would make this valid service, but check with a local attorney before you do anything for such local attorney will know what is meet by "Suitable age and discretion".
Please note, I do NOT know what Arizona Law is but in my home state I have had a whole rash of cases filed by Plaintiffs where the underlying debt is either out of statute (The statute of Limitation has run on such debt) or they do NOT follow the rules as to what should be in a Complaint (I do NOT know what Arizona requires, check with a local attorney, but most states require NOT only that the complaint contain the fact you are being sued but by whom and why and often require at least a copy of the underlying contract),
Furthermore you hint that a hearing date has been set, that is generally done in a Justice of the Peace/ Magistrate Court NOT a County Court (in many states called a "Court of Common Pleas). In many states you have the absolute right to file an appeal from a Justice of the Peace (Or what ever your home state calls their JPs) to Superior Court (or what ever you State calls its County Courts, Superior Court seems to be the name for such court in Arizona, in many state it retains its name it had in England, the Court of Common Pleas).
The problem is the appeal time is tight AND controverted. Thus I recommend your parents contact a local attorney to see if they have a defense, if the lawsuit has any merit, and even to see if any Judgment from such lawsuit can be used to attach the defendant's property (I live in Pennsylvania, one of two states that prohibits attachment of wages for most debts, it is permitted for Student Loans and Child support but NOT for most other debts, Pennsylvania also prohibits the selling of marital property for the debt of one spouse). Your state will have different rules and a local attorney will tell you if the Judgment is collectible. If it is NOT, who cares how many Judgment your parents have, but if it is collectible and they owe the money and the Complaint is valid, they only defense may be bankruptcy, another issue to discuss with an attorney.
The Filing Fee for Bankruptcy is $299 plus what ever the Attorney wants to charge. There are counseling you have to go to pre-bankruptcy and post Bankruptcy (and pay for, cost about $50 each) an attorney will talk you you about them. Now, under present Bankruptcy laws, you have the option of taking your State's exemption or the Federal Exemptions (In Pennsylvania the State Exemption is only $300 so all my clients take the Federal Exemptions). The Federal Exemptions permit a debtor to keep their home (If it is being purchased) if they equity is less then $25,000 (i.e. the difference between what the house is worth and the mortgages on the property) provided the mortgage is being paid, they can keep their car if the equity is less then $2500 (again the trade in value of the car less what is owned on the Car) provided any payments on the car are made. $10,000 in other items (Which can include a second car if one is owned by your parents). Please note the valuation is what you can sell the property for NOT what you paid for it. I tell my client what you pay a $1.00 for, you can sell for a Nickel (.05) unless they is a market for that item (and we are talking only about Homes and Automobiles today).
Notice, most legal defenses are state based, so tell your parents to see a Lawyer, if they are low income (Roughly 125% of the poverty Level) their Local Legal Aid agency can help them (What your local legal aid agency do is set by the Local Agency based on their Budget, and I expect them to drop what they cover do to the present budget crisis in most states).
125% of the poverty line for a family of three is $18,310 a year or $1,566.66 a Month:
http://aspe.hhs.gov/poverty/09poverty.shtml