How are you calling it in the named.conf file? Did you increment the serial after you made the change and reload the service? Are you sure your upstream delegated this ability to you and didn't just allocate the IPs and that was it? dig 244.83.112.217.in-addr.arpa PTR +short yields no results for me. I tried @ns1.unlimited-host.org and @server1.unlimited-host.co.uk and got nothing back (I even tried the IP), showing that the name servers you claim to use don't even report it back, which should work even if authority wasn't properly delegated/setup. What name server should we be checking against?
it still doesn't return any result. Thus, it would appear that the changes either haven't been committed to your very own DNS configuration/service, or you have something missing, or a problem on your end.
Regardless if your upstream properly delegated authority for you to set PTR records on your end and have them actually work, it should return a result at the DNS servers you have this set up on, but it doesn't.
If you can answer the above questions I asked, I might be able to help you with a suggestion or something.