Correct, I had the same GSuite setup (for the purpose of keeping backups) and they kept billing me even after they set my drive to read only. They only stopped when I decided to cancel the account myself. IIRC the minimum around $10/mo. Technically you were supposed to have 5 employees in your GSuite “company” at $10/mo per license, but they didn’t really check, so I just had myself as the sole employee.