It is 100% understandable. Some very small changes to make it more natural would be: To whom it may concern, Two months ago, I applied for iH in Ecuador for the purpose of taking the CELTA course. After being accepted, I began arranging the travel. I soon realized that I needed transit visas for the layovers, which made it very complicated. For this reason, I believe that it would be wiser if I applied to your center. Would you please advise me of the application procedure? Thank you in advance. Best regards, Full name

To whom it may concern, I applied for iH in Ecuador after taking the CELTA course about two months ago. After being interviewed, I was accepted, but when I was looking for flights, I realized that I needed transit visas for the layovers, which made it very complicated. For this reason, I realized that it would be wiser to apply to your center. Could you please tell me the proper protocol for applying to your center (and if i need to be interviewed again)? Thanks in advance. Best regards, Full name