It's a NO for DAWN WING

I Have an online shop and They have lost numerous of my parcels and now I have been struggling for a few weeks to get a refund for the parcels lost. I had to resend the items so it cost me double product cost and double shipping which is ridiculous and now they only want to refund me in credit to use with them, but I have cancelled my account and know I need to use the credit with them again. Also they take AGES to respond to my matters and just lost ANOTHER parcel I was notified with yesterday from my unhappy customer... :/ NOT HAPPY