The seller does not have to admit that he made the statement for a court to find that a preponderance of the evidence shows that he must have. And if a buyer asks the seller for a description of the condition of the goods and the seller responds, that is an affirmation of fact that becomes part of the bases for the contract and it creates an express warranty.
What does excellent condition and barely used mean to you? Would you think that the camera was in like new condition or that it means that the grip was falling off? OP's problem here is that they inspected the camera and accepted it. But we are speaking of the law.
You disregard that the seller acknowledged in writing “Ok, no problem” is part of a conversation (in writing) that OP wanted to return the camera. You must include the context of the exchange to understand what the seller agreed to.
The seller agreed to a refund and then cut off all communication. Did the seller know that the camera was not in excellent condition or barely used? How do you think a court would view that behavior?[1] Respondents answer that there would necessarily have to be a new or fresh consideration to support any such new promise or warranty. In support of that contention they cite William A. Davis Co. v. Bertrand Seed Co., 94 Cal.App. 281, 288 [271 P. 123], wherein this court said: "But it is respondent's contention that after the receipt and acceptance of the goods and the payment of the price the defendant made certain written statements in its correspondence with the plaintiff which constituted a warranty.
You can argue semantics if you like. Courts however, use the obvious meaning to an average buyer in a sales contract. Excellent condition and barely used? doesn't conger up images of a grip falling off.

