Dear Sarah,
I hope you are doing well. I am writing to sincerely apologise for failing to meet up with you during my trip to Manchester last month, despite my earlier promise that we would catch up.
I feel terrible about the situation, especially since I know you had cleared your schedule for me. The truth is, my trip turned into a complete disaster when my laptop was stolen at the station on my first day. I spent the entire duration of my stay dealing with the local police and frantically trying to secure my accounts. I was so overwhelmed and stressed that it honestly slipped my mind to contact you until it was already far too late.
I really value our friendship and would love to make it up to you. I am planning to head back that way in mid-October for a work conference. Would you be free to grab dinner at that Italian place we used to frequent on the evening of the 15th? It would be wonderful to finally see you properly.
I look forward to hearing from you soon.
Best wishes,
James