【正确答案】Dear Victoria,
I am writing this letter to apologize for my negligence. Please understand that I did not mean to host a party without telling you. It was a mistake that I felt genuinely sorry for.
I will greatly appreciate your understanding. You can imagine that I was so overwhelmed with the preparation work that I had no time to spare on checking the invitation list. I know you must feel really disappointed to learn that I left you out of my party. Please do believe that I feel the same way with you. Therefore, I am going to host another party at my home on next Tuesday. I'd like you to be the first one to receive my invitation. Please show up and accept my sincere apology in person.
Again, I want to say sorry to you. Hope you all well and see you next week.