Claims not paid

I visited the hospital in August 2020. Later on I received an invoice from the hospital which I forwarded to Elixi. They had claimed that they settled an amount with the hospital I visited, only to find the amount was not paid. I followed up with the claims department at Elixi who assured me that the matter was resolved. In December 2020, I was approached by the collections department stating that I owe and will be put on the credit bureau if I don't pay. I forwarded all communication to the doctors office regarding the issue. Elixi still has not come back to me after numerous reach outs regarding my claims. I've found them very unprofessional at this point.