Dear Jenny,
I am sorry and f know you are very angry that I have not attended your birthday party.
I was not able to be at the birthday party as I had a meeting in my office which was urgent and not planned. Trust me I tried to postpone the meeting but the clients were not ready to do so. I know we had planned a lot for your wedding, but I am sorry because of me you were disappointed. I also wanted to be with you on your special day, am too feeling bad about it.
Please accept my apologies, t would come and meet you soon. I know I cannot make it for what I have done but will try my best
Miss you,
Alan