Terrible service and being made to feel like a ****

Missing items from an online order and told that they find no discrepancy in their delivery system, and that the items were delivered when they were not. The parcel was tampered with. I provided pictures of the damaged parcel. I ordered 3 items, only one was delivered, the item delivered had hand prints all over it. After going back and forth via email, no one bothered to call me back and call centre agents could not help with my queries. I was told I would not get a refund as they packaged the items, since I don't have the items something must have gone wrong in transit. After being a customer for 20 years. I will no longer be using their services. The customer service is terrible and I will be taking my case to the ombudsman.