Parcel delayed

I have my parcel from wish that i purchased early last year and as per wish when i track them they've been to dundee post office for a very long time but still hasn't receive the recept for collection some they arrived last year in June but no action has been taken when i visited them they told me they have lots of parcels they cannot help me which means they kept my parcel for some unkown reason i was told i had to parcel but when i get there they couldn't find them