One export company in China made an offer to a foreign customer on October 25 by telex : "the offer is open subject to your reply reaching us before or on October 29 ". After receiving the offer, the foreign customer sent us a telex reply on October 27. The reply is as follows: "accept the offer of October 25 but reduce your price by 2%. " We were considering the suggestion of the customer when the customer telexed us on October 28 to revoke the reply of October 27 and accepted our initial offer(October 25).
Question: According to United Nations Convention on Contracts for the International Sale of Goods, can the customer revoke the telex reply of October 27 and accept our original offer？ Is this deal concluded？
(Translate the case into Chinese and the answer the question)
Helpful hint: This case is mainly about the offer and counter-offer.