Rewrite the given text with correct english and punctuations, expanding the internet slangs:

Input: fyi i am not keeping well today therefore will ttyl
Output: FYI, I am not keeping well today, therefore, will TTYL.

Input: the message transcribes to lysm
Output: The message transcribes to LYSM.

Input: let em know ill brb
Output: Let them know I will BRB.

Input: storewide sale this weekend only show this text at the counter for an additional 10 percent off btw store hours are 9 am 7 pm sat and sun
Output: