Will RM look for my lost parcel?

A parcel was sent via RM Special Delivery Guaranteed 1pm on the 9th Decmber. The tracking details show 'Item despatched to Romford MC' on the 1th Dec and then nothing since.

I phoned RM and they told me to put in a claim to investigate further, but looking at the website it looks like they just reimburse costs rather than try to actually find the missing parcel.

I'm not interested in being reimbursed, but need the actual parcel (it's work related and not worth anything financially, but logistically is valuable).

Is there any way that RM will look for the parcel - if I phone Romford MC would they help me? Anything else I can do?