Good day I just wanted to send a complaint to you about a online company I recently ordered from, my package was supposed to arrive already and I haven't received anything as they keep emailing me to say I have to still pay my tax bill after I already did

Good day I just wanted to send a complaint to you about a online company I recently ordered from, my package was supposed to arrive already and I haven't received anything as they keep emailing me to say I have to still pay my tax bill after I already did and keep providing them with proof of payment too, at this point I'm highly frustrated and do not know what to do about the situation as I emailed so many people already just to end up with the same end result. The company whom I ordered from is Shein and as if read my package is being held at Buffalo logistics until I pay a fee of 110 which I already did, I would appreciate any assistance or feedback feedback please