This is difficult as the Smart Hub is showing as returned which means they must have opened the package and entered the contents into the system. It must be fairly unlikely that they scanned in the smart hub but not the mini hub?
So ultimately it is your word against the word of the staff at the depot, and you don't sound absolutely sure?
The only way forward is to phone customer services and discuss the situation. I recently returned a smart hub which didn't get entered in the system so I phoned them up and they were happy to mark it as returned. However in my case it was the only item that was wanted, there was no charge for not returning it, and I had the tracking stating that it had been delivered. It might be different if you have a fee to pay for non-return.
