Reverse dns is a bit tricky for public IP networks. I guess you don't own the whole 188.8.131.52/24 subnet, so you cannot setup your name server as authoritative for the 2.69.217.in-addr.arpa zone.
, it looks like the IP range of your network is 184.108.40.206-220.127.116.11.
So you need to contact your ISP and tell them to delegate you the 18.104.22.168/28 chunk for the above subnet.
Then you can read this
document to see what you have to do to configure your 48/22.214.171.124.in-addr.arpa zone.
If you run on problems with this, post your 48/126.96.36.199.in-addr.arpa zone file to let us help you better on this.