Squarespace / WordPress Forwarding

Hello everyone,
First of all I do apologize If this not the right place to post this topic. First of all I`m a junior web designer and have been using WordPress for a few years now. (Both for my clients and myself)
Im currently doing this project for a vocational education & training company. Before I took over the project they had a Squarespace based website and their actual domain (https://www.tangentetraining.com.au) was linked to this Squarespace website. When I tried to install WordPress on the actual websites hosting, I had to unlink this Squarespace website from the actual website because I was going to upload the WordPress design I have done for them. As soon as I unlinked these domains I started getting this Squarespace page saying that my custom domain mapping may take up to a day. I got in touch with several people from Squarespace and they told me that my DNS was still pointed to their DNS. I got rid of that A record and was still getting the same error but for the last few hours even that page hasnt been coming up. All Im gettin is that default Google Chrome could not find https://www.tangentetraining.com.au/

I was just wondering why this is happening? Is it because the new DNS configurations are being processed right now or am I missing something.

If there is anyone out there who could could help me I`d really appreciate it as tomorrow is the deadline.

Cheers
Hakan