5 days later, i hope your funds are credited already? Kucoin is a very good exchange which i use and i have never experienced this kind of situation as well. Did you crosscheck the erc-20 address with which you deposited? And did you also check your kucoin deposit history to see if there is any information at all. I will advise that you chat with an online support to get instant replies too.
While depositing to any exchange platform, do ensure that you scan the qr codes for deposit address; if you cannot scan the qr codes; ensure to clear your clipboard to ensure that you have only the deposit address to paste to the column while making deposits.