I returned the oxygen tank and concentrator, to Pacific pulmonary last november 2018 Pacific pulmonary has been notified as have you as have left messages concerning this issue. I was supposed to get a response from you credential regarding this issue and I am fed up with continued bills and phone calls. I will not be paying any bills until this issue has been resolved. I have bought my own equipment. I believe the insurance company may still being billed as I am. Please deal with this issue. Thank you [protected]@gmail.com [protected]