Quest Diagnostics Double billing and sent account to collection Cincinnati OH

I went to Quest diagnostics at the address 2365 Quimby Rd Ste 211, San Jose, CA 95122-133 for the two lab tests. They promised to send the above lab test results to the doctor's office in 3 to 4 business days.  But they did NOT do the tests and did not send the test results to the doctor's office. When my doctor contacted them and inquired about the lab results, which never arrived the doctor’s office, Quest diagnostics informed that the tests could not be done and advised the doctor's office to send the patient (me) again to a Quest Diagnostics. Hence I obtained the doctor’s order again and did the test at the Quest diagnostics location: 2581 Samaritan Drive, San Jose, CA 95124-4112. This time Quest diagnostics did the test and sent the results to the doctor’s office in about a week.

However, Quest diagnostics billed twice for both dates. I called them multiple times at 1-800-758-6047 but there was no human to talk with, they only accept payment via an automated system. 

Instead of being sorry for not doing the test on time and being sorry for doing the double billing, they forwarded my account to collection to ruin my credit history.