I am sick of having to open a dispute from the poor vendor when Aliexpress is cheating...

I am sick of having to open a dispute from the poor vendor when Aliexpress is cheating me AND them by charging a sales tax ONLY since Oct *, ****. The vendor shows me he does not take the funds and then I am told that Aliexpress denies me as it is a "customs" tax and my fault. Also in a chat with their agent, they TOLD me to open a claim but there is nothing for my issue and no one seems to read the NOTES because they respond stupidly only to the fake drop downs I must use. Lying and cheating me of *% on every single sale starting ONLY since Oct. *It is ILLEGAL to charge sales tax from a foreign country to my state- I know they don't file a tax return, HA, and my complaints all get responded to "all customs tax are your responsibility". My sales are under $* and customs only begins at $**-This is a new issue and they are cheating me!