You are lucky, last month I sent back
two phones, one I tried out for two days the other one I never even broke the seal on the box,
they were sent back via different carriers and one week apart.
Last week I received an email saying I had sent back an empty box and despite sending the receipt from the carrier with the weight on they refuse to even investigate that they might have criminal activities within there returns department.
Two days ago I received another email saying they had received another empty product box for the second phone and was disposing of the box and I would not be getting a refund, I felt sick in my stomach. The second phone I had sent by a different carrier and had never been opened but they would not listen to my request to investigate things, they choose to believe I was trying to be fraudulent by sending back two empty boxes.
I told them if they think I'm a criminal get the police involved because I am totally innocent, plain working guy who is now over £2300 in debt on my credit card.
I have written to the CEO of Amazon UK with no joy.
I understand mistakes happen but they are a lazy company that it is easier to blame the consumer than to investigate their own staff.
This experience has made me ill and I never want to deal with Amazon again, it even hurts to have my Alexa devices around the house and may remove them.
I have given up hope of ever getting any refunds because there is no one to speak to only customer services who say its out of their hands and for the sake of my heath I have to let it go and treat as an expensive life lesson but I will never deal with this company again.