1) Hire a copywriter that will explain to the client T-Shirt is custom made / printed just for him/her.
2) Make some videos how Amazon makes the T-Shirts and explain the process in a friendly way.
3) Explain to the client that the "vinegar smell" is normal thing. That is also the job of the copywriter.
4) If the client doesn't like the T-Shirt he must return it. Don't let clients keep the damaged or undesired T-Shirt for free. Give all returned T-Shirts for charity.