What does the tracking exactly say - who's the courier...? DHL...? UPS...? FedEx...? That isn't something that would appear on tracking info as customs has no access to it (and it's automated). If it had been seized you would have received a letter from HMRC/Border Force advising you of such. When it states "1-2 days delivery" that's from the vendor to the UK, ***NOT*** from the vendor to your door, as neither the vendor, nor the courier, has any control over customs. Customs could take weeks.