There must be a reason why Shopify keeps deactivating your store, check their policies to ensure you follow all the acceptable use policies. Contact Shopify again and ask for clarification to avoid making the same mistake again, and check your email ...

Can you share your store URL so I can further assist you

You can also edit this in the theme code, but the process varies depending on the theme you are using.

Hi, it is easy, go to your online store,  click on the 3 dots beside customize, select theme content from the dropdown. Search for powered by Shopify and delete

You need to make the changes in the store theme liquid before you can modify it in the theme editor