Need to change MAC address on NETGEAR Nighthawk C7800

[epochdad]

I left an open email relay on my machine and of course it was exploited and now my static IP is listed in sorbs and spamhaus. I have begged them to delist my IP but they said they can't and I have to contact comcast. I contacted comcast and they wont issue me a new IP address. I am unable to access many forums due to this problem and I was curious to know if there's a way to "spoof" the MAC address so my static IP will change?

I've tried unplugging the router for a full 24+ hours to see if the IP would change it did not.

[FURRYe38]

Nope. MAC address is hard coded.

Only the ISP can change the WAN IP address which would help. 
If the ISP will not help change the WAN IP address, then you may need to get a different modem. 

[epochdad]

Any good recommendations on a router/modem combo?  Preferrably one that can change MAC address within the firmware? ...that is if ISPs even allow routers that do that anymore... this would be for a family of 6 gamer addicted kids and a mom & dad who work from home + 1gbit Comcast speed?

https://www.speedtest.net/my-result/d/bb743b68-a923-45c2-9e99-a20277de8225

[FURRYe38]

I recommend getting into a separate modem and external router combination. 

ISP modems have never been able to change MAC addresses, same for modem router combo gateway units. If you get a stand alone modem and a external router, routers have much more flexibility to be configured and some also include MAC cloning abilities as well.