I feel your pain as the same thing has happened to me. Last week they turned up an hour early (12.30) so I missed the delivery, when they were supposed to deliver it between 13.30-14.30. Then on the tracking it said they delivered it at 13.40. Thankfully we've got a Ring doorbell which records the footage. I tried to get it delivered the next day but DPD sent it back to EE instead.
I then did the upgrade again and it was supposed to be delivered on Sunday, something urgent cropped up so I rescheduled the delivery to yesterday. I was home all day and I hadn't received a text from DPD so I contacted them, they started asking me about an IMEI number, I told them that I had no idea what it was as I didn't have the phone!! I then downloaded the DPD app, it flashed up that my phone would be delivered by 10pm, at 5pm it flashed up that it had been delivered which was odd as I was in and the Ring doorbell didn't pick anything up.
I've now raised a case with DPD and I spoke to EE this morning, if you upgraded online like I did phone 0800 079 0531 which is for Digital Sales, I was holding quite a while but I did speak to a helpful guy that has raised a case and someone will call back in 24 hours.
It's so frustrating. Good luck I hope that you manage to sort it out.
