Sometimes Google may say one thing, but you may have other issues. Adding the Refund policy and Terms of Service in the footer is correct.
I recommend having a look at the following policies:
The most common issues are:
Not adding full contact details page linked from the footer (email, phone number, address, contact form): https://support.google.com/merchants/answer/6363310?hl=en
Not having a valid checkout: https://support.google.com/merchants/answer/9158778?hl=en
Selling products that are not allowed: https://support.google.com/merchants/answer/6150006
Selling products that are not stocked: https://support.google.com/merchants/answer/6150127#:~:text=Unavailable%20promotions
Not adding any added content, and simply copy-pasting other sites
Having multiple websites in the same niche
Not being honest with what you sell or how you portray the business
Having a low trust factor or no track record of order fullfilment
You can ask Google for specific examples of policy violation. To do so ask here and check the box, I need more info : https://support.google.com/merchants/contact/suspended
Hope this helps.