On July 30, 2021, A wrote B a letter offering the sale of his bag. On August 26, 2021, B wrote a letter of complete acceptance of the contract which was received by A on August 31, 2021. But on August 30, 2021, A had already written B a letter withdrawing the offer which was received by B on September 1, 2021. Is there a perfected contract of sale? Explain your answer