Hi there and welcome
Can you Save the the sheet as Excel and not CSV. Then open the Excel document, convert the whole sheet to text format, and save as .csv.
It should keep them as text format.
Let me know how you go please.
I can also do these steps for you, and have made a request via Additional Services. This is optional, and if you choose to do this, I can, with your permission, remote into your computer while you watch and do all these steps (and deal with any problems that arise during them) for you. Or if you do not choose to take this service, we can continue here. This is no problem at all. Just let me know please.