The purpose of tracking is to prevent buyers from opening false Item Not Received Disputes.
If your item has not arrived in 20 days from Canada or the USA (or 30 days from Asia), open a Dispute in the Resolution Centre at the bottom of this page,
If the seller really did send you a fake number he won't be able to prove delivery and you will be refunded.
So either it arrives and your concern is for nothing or it doesn't and you get your money back.
No worries.