Import tax/mail package question

So, I stupidly ordered some contact lenses online with a total value of over 3000NT. I was well aware of this tax threshold, but since I’d ordered from the same supplier a few times before without issue I did a re-order without thinking. Had it sent standard international, which the supplier said would take something like 12 business days, but then added with customs issues it can take up to 6 weeks.

Anyway, 6 weeks is up and I haven’t received any kind of notification at the shipping address, nor at the phone number I provided on the order. Previously when I ordered something online over 3000 I was contacted by UPS and asked to fax in a waiver to agree to pay the tax…this one is standard international though so I guess I’m going through the post office.

What’s the best way to track this thing down…local post office or is there somewhere else I should be asking? Any help would be appreciated!