HR not professional - Line Worker Europastry Employee Review

I started the job waited the time period to get benefits and whoever put my information in the system put my start and end date as the same date for benefits, now I got a card in the mail but they wouldn't pay anything like I didn't have insurance and have been trying to get in touch with someone in the NY office but no luck even had a lawyer contact them still no response no luck so now I have been going back and forth with the doctor telling him that there is nothing I can do the Hr department has to fix my start and end date they have to correct it. Now I am fighting this on my credit in collections.