We will send one sample to you this afternoon. However, the factory forgot put the warning card into the giftbox. Our QC will accompany with you and show you the warning card during the inspection on tomorrow.
We will send you a sample this afternoon. Unfortunately, the factory forgot to put the warning card in the giftbox. Our QC (? Quality Control Manager?) will accompany you and show you the warning card during the inspection tomorrow.
Notes: Does QC stand for Quality Control? If so, it's impossible for Quality Control to go anywhere with someone. It is presumably a member of staff from the QC department, so you need to state that.
It's just "accompany", not "accompany with". Accompany means "to go with".
We simply say "tomorrow", not "on tomorrow". We use the preposition "on" if we are specifying the day of the week. "There will be an inspection on Tuesday", but "on" is not used with yesterday, today or tomorrow, or any of their variants.
