I guess we all fail to go by the old adage: You get what you pay for".
The Vevor lathe was only $310.00 discounted from $500.00
I am old enough to know better!
IMO that adage should read "you very rarely get more than you paid for, but will often get less".
Vevor is like buying things at walmart, no one there knows anything about the item other than what the add says (if that), spare parts are not available, the quality is hit or miss (in the case of Vevor and lathes more miss than hit). you can overcome some of this buy saving the case it came in, checking it immediately, start squawking immediately and be prepared to return it immediately. most times when something is wrong they will do a couple of things like just send you another. you have more leverage with someplace like Ebay / Amazon with free returns spelled out if you pay attention/comply with the rules they are very interested in making you happy if they are about to eat the return shipping.
It is a different buyer experience and you have to do a lot more work thru them than say a PM or Grizzly but you can get what you want if your want is reasonable and you put the effort in, you are not going to get a south bend heavy 10 or a hardinge HLV so if that is your expectation then you need to look elsewhere. If on the other hand you want a hobby machine and are willing to play the returns game you can get a fun hobby machine for little money.
with all that said Vevor would not be my first, second or 5th choice for buying a lathe.
I have bought a lot of things from Vevor and have been happy with most if not all of the items, from hose reels that came in broken and after i squawked loudly they just sent me a replacement and told me to keep the first one, which i fixed and it now works fine. to a dividing head that works fine for my use etc.
My advice if i were in your shoes is start squawking and see if they just send you a replacement with you keeping the original you may end up with what you originally ordered and a lot of free spare parts.
I would not volunteer to fix it or install parts, it is their responsibility to get you a working item. I originally did not catch that you had purchased this thru Amazon, that being the case it just got easier for you just just start asking for a return on their dime and see what happens, i bet that they can then look up the batch codes for themself