Based on the info that you supply, I would say that you are 90% to blame. Their system of processing was only slightly flawed, as it did not pick up the anomaly.

I recently sold some things through ebay and sent them with city link.

Apparently I have rather stupidly stuck the same shipping label to both parcels which has resulted in both parcels going to the same address.

I can't understand why city link took both parcels when the order would of shown that they we're supposed to go to different places.

I just don't know where I stand with this because although I messed up city link should of left the parcel that was addressed wrong.

any help would be great