McDonald’s vanderbijlpark false advertising

The restaurant claims to have WiFi but doesn’t wanna give password, I went to McDonald’s Vanderbijlpark with my family for a meal and I wanted to redeem a voucher from their cellphone application then I wanted to use their WiFi to connect I was told the owner of the store doesn’t allow them to give passwords, I would like clearity as to whether the WiFi is available to customers or this is false advertising!