If you owe the debt it is only going to delay the inevitable. If you were served with the complaint then you only have 180 days to set aside the default. If you were never served then the 180 day rule does not apply. Talk to an attorney.
This is just my opinion and not a comprehensive answer. You assume the risk because this answer may not apply to your situation depending on the facts.
CCP 473.5 is one type of motion. You may have another basis for a motion to vacate the judgment. You can base the motion on non-service and the court's lack of personal jurisdiction over you. You should at least talk with, and probably hire, an attorney to make this motion. After your papers are filed with the court, there may be an opportunity to negotiate. A negotiated settlement should include vacating the default judgment, so that it does not negatively affect your credit, and how the account is reported to the credit reporting agencies.
Your post indicates that you likely were not personally served with a Summons and Complaint in either case. If this is true, then you can file motions to set aside the default judgments.
I recommend that you contact a consumer rights lawyer for help in getting the default judgments set aside.
You will need to obtain copies of a document known as a Proof of Service of Summons [one should have been filed for each case]. The process server who claimed to have personally served you signed a declaration under penalty of perjury stating the day, time, and location where they claim to have personally handed you the lawsuit papers. If the process server lied on the declaration [sadly, this is increasingly common in debt collection lawsuits these days], then you will need to re-trace your whereabouts for the date(s) you were allegedly served. If you can prove that you were not at the location on the date and time shown on the Proof of Service, then the Court should set aside the default and order the return of the levied money.
One other observation: if you have multiple judgments against you already, why not consult with a BK lawyer to see if a fresh start would be the best way to deal with your debt problems? The overwhelming majority of BK lawyers offer free consultations.
Please note that, while I am a lawyer, I am not your lawyer. This information is for general educational and informational purposes only, and is not legal advice. You should review your particular situation with a qualified lawyer of your choosing.