OFFER AND ACCEPTANCE

On Sunday, 1st July 2019, Alvin heard from his friend named Nicky, that Theodore, a former colleague wishes to sell his nursery business called “Chip n Munk” for RM2 million. Alvin visits the nursery and seems to be interested to purchase nursery business. Theodore wrote a letter of offer to Alvin on 10th July 2019 stating that “if Alvin agrees with the offer and responds through a letter within a week, the business will be sold to him.” However, Alvin replies and says that “he can only afford it if he could pay for it in four installments”. Theodore does not respond. Later that day, Theodore receives a message on Facebook from his friend, Simon, saying “I heard you are selling your nursery. I would like to buy it for RM1.9 million.”
On 16th July 2019, Alvin sends a letter by PosLaju Malaysia services to Theodore accepting Theodore’s offer and in the letter, he enclosed a cheque for the sum of RM2 million. On the same day, Theodore replies Simon’s message on Facebook accepting Simon’s offer and giving him instructions on the payment details.
On Sunday, 17th July 2019, Alvin heard from a mutual friend that Theodore had sold his nursery business to Simon.
On Monday morning of 18th July 2019, Alvin approaches Theodore at his nursery and asks Theodore if he has received his letter to which Theodore replied that he had not. Theodore also informed Alvin that he had sold the nursery to Simon for RM1.9 million. Alvin was disappointed and very furious. On returning home that evening, Theodore finds Alvin’s letter in his room. His wife informed him that it came by courier that afternoon.

Advise Alvin on the two matters below:
i) whether he has any action against Theodore for breach of contract; and
ii) whether Theodore could revoke his acceptance.