I wish you would help to check (A letter to complain...)

Dear Sir or Madam,
I am writing to bring to your attention some issues with the local subway service of line two.

I take the subway line two from Puxi to Pudong at eight o’clock every morning. This week, the subway has been being stopped in the middle of the way for two times due to a the mechanical problem. Every time the stop lasts around 15 minutes. This has caused me to be late to work the delay to my work and to receive the complaints from my boss.

Passengers who on the subway keep complaining and feel are very frustrated.  by long waiting. Due to this unexpected stopping, Many people are late for their work or school. Also during while the mechanical breakdown, the air conditioner is being stopped as well, which leaves the compartment unventilated and this is extremely uncomfortable.

I would like to suggest that you need to find an expert to solve this mechanical problem immediately or replacing it by a new tube with good condition so that you can maintain a good public transportation service.

Please I hope you will address these concerns as soon as possible.

In the US we would write Line 2, with capital L, because it is a formal name, maybe different in your country.  I mostly shortened the sentences to make it more 'punchy' or direct. Because you are angry! I would also be angry!