Need REAL IPTABLES PRO to help fix iptables problem

I have hired TWO so called professionals so far to help get my iptables working correctly and each time, the person left me with a mess that didn't work once they were done. One problem after another such as rebooting and losing settings and other issues. The server is a Centos7 being also used as a kvm vm host so using NAT. The is using iptables rather than firewalld but I would have preferred using firewalld. I need someone to get on the host with me using screen sharing, then fix the current problem then make sure that we can add rules to the host without breaking iptables again and not breaking access to the nat based vms.