Normally it is best to assign the name servers of your host to your domain name, in this way all DNS records for Web/Ftp/Email/DBs will be configured automatically and you will be able to manage DNS from your hosts' control panel. Ask your host about what their NS servers are and Ask your domain registrar about how to set those NS records on your domain name.
You can find our name servers at the following link:
https://www.servwise.com/en/knowledgebase/79/our-dns-name-servers.html
You should not simply change the NS records in your domains DNS records, these NS changes are in the root domain, not your own domain and you will normally find a separate option for changing Name Servers apart from the normal DNS editor. Changes are in the top-level domain e.g. .com .it
The following link could be helpful to you:
https://www.servwise.com/en/knowledgebase/426/How-to-use-a-domain-registered-with-another-domain-registrar-with-our-hosting-by-assigning-our-name-servers.html
If you need help, please contact support.
