Returns

I have been getting the wen hair care products which I love. I changed the package i wanted and returned a package in November. I made the mistake of not using the signature required option at the post office. They keep sending me a bill, i have called them every month for the past 5 months. This past month they said they would send an affidavit saying i returned the product. I never received the affidavit and now they are sending me to collections, they send a bill with no contact number. I am going to cancel mynorder.