These people called said I had two hours to respond or they would proceed with further legal action. They left a case number and a phone number. 213-761-4910

These people may be using illegal tactics to scam money from people.  They buy debts then immediately threaten to sue!  A woman called for one of my employees and when I told her we don't accept personal calls at work, she demanded to speak with the employee's supervisor.  No way!  Totally rude and aggressive!  A google search on the company LPS or LPS Group revealed that they also use 888-256-6985, 714-230-7491 & 619-746-8458.  One post shared this information:
LPSG is really LSAG. LSPG is their DBA. I hired a private investigator. The real office is at 12062 Valley View Blvd. Its off Valley View and Chapman in Garden Grove. They are debt collectors who use illegal tactics to scam people breaking the fair debt collection act and need to be stopped. They change phone number and names they use often.Call your bank to report fraud and get a refund if you gave them money and then talk to a attorney. You can also report them to http://www.consumer.ftc.gov/articles/0149-debt-collection or
http://oag.ca.gov/consumers/general/collection_agencies10