Are these sentences grammatically correct?

As you may recall, I requested the management in January for additional manpower for our department, but I haven’t received any information regarding this request. I have been repeatedly following this request up with this management since we have work increase in projects but no reply has yet been received. As you may have heard that the last few weeks were crucial in our operations , there are only some works in which we could complete on target date and other works were completed after the scheduled date, and we couldn't maintain our day-to-day activities because of lack of manpower. Therefore, we have been receiving complaints from everywhere.