New Account - NBN Bundle

Level 2

Good Morning, 

I recently signed signed up to TPG NBN Bundle as I moved house. I have collected the Modem from the Post Office, however when they NBN tech arrived this morning, he insisted he needed to cut through walls to install the NBN. I live in a rental property and was never advised this would be neccessary nor will it be permitted. Therefore, could you please urgently advise if I can use my current modem to access TPG internet through 4G and do I need to change the plan I have signed up for? 

I have tried phoning/ online chat support but neither are working. 

Kind Regards,