From a person, a business, a FB page, a TikTok ad, a Line ad, .....
The thing you bought was it legal, illegal?
How long have you been waiting fore delivery?
Any communication with the seller?
If you talk cryptic, it is hard to give advice.
No always, if there is an obvious fault at the sticker price for instance, they forget 2 zeroes at the price of a car then they won't have to sell it for that price.
Because business who pay expenses for their workers need a tax bill where it does mention VAT. They can deduct the VAT paid from the VAT they charge.
People do need to know the law, ignorance isn't an excuse for disobeying the law.