more of a wwyd but can't find the topic

I've just had a text from a large online retailer to say that my parcel is delayed and they are trying to sort out delivery.

The item I ordered is one that has to be signed for by an over 18 year old according to the notes on the order but it actually arrived the other day with some other items and I wasn't asked to sign for it.

I went on to the website to see if I could cancel the delivery, there is an option to cancel it but that goes to a screen for a refund which obviously I'm not entitled to so I'm going to end up with two packages and have to return one as I doubt I'll be in when it arrives.

I used the online chat and they say that they can't cancel the delivery and that I'll have to refuse it if I am in or send it back if I'm not. I'm not happy about this as I'd have to pay to return it and then ask for a refund.