It's the weekend and some companies do not work on weekends.
Try again on Monday, but keep time zones in mind. China is 13 hours or more ahead of Ontario. for example.
If you cannot get through, or if the answer is not helpful, open an Item Not As Described dispute. Look under Customer Support up there in the top right corner.
If the seller offers an replacement, do not accept. You want cash. Replacement is slow,especially from overseas and what you get may offer different problems.
You may be asked to return the unwanted items to the seller with Delivery Confirmation. This can be very expensive, especially to overseas.
You might be best off to ask for a partial refund with no return. The seller does not have to accept this offer.