Do I contact the company or Royal Mail? Stolen parcel

[Mounjarooo]

RM delivered a parcel to me today but I wasn't in.

They left it on my front step, I don't have a front garden, my door is directly on the pavement of a busy avenue that has an alley next to it so lots of people walk through.

I have proof via the RM photo that they just left it in plain site, no attempt to hide it.

And someone taken it.

Do I contact RM themselves or the company I bought the item from?

Am so sick of them doing this
I've said so many times in my preferences not to!!

Or both?

The seller, they claim it in their insurance via RM

The company, it’s up to them to claim from RM, depending on their contract with them.

I think that the official rule is that the company have the contract with the courier. You don’t. it is their responsibility is to get it delivered to you (not outside but to you) safely so if that doesn’t happen it is the responsibility of the company to chase the courier and replace or refund you. It is not your job to chase the courier.

Ok, thankyou.
I've messaged the company