[ethmoney6]

I ordered a jacket from Zalando ES and claimed DNA they asked me for a binding legal statement and I filled it out, after a week I contacted them again via live chat and an agent told me they had just accepted it and that I would be refunded in up to 7 working days, the next day I received an email that zalando would not refund me because the shipping company claimed they had delivered it correctly.
What should I do in this case?
Any comments are welcome and your opinion would be very helpful.