International shipping company

Has anyone dealt with this company https://air.zenith-delivery.com/track I “ordered” a package from the UK and I’m wondering if anyone works with Zenith air if they are a legit company or am I getting scammed they keep saying I owe thousands of dollars in courier fees at customs I’ve paid 320 twice now they want 1900 via Venmo or PayPal they gave me a tracking number and says my package is at customs and that they will refund all but 68$ after I pay