Changing gateway IP without using router's site.

I have a Cisco DPC3825 modem/router combo, that I got directly from Shaw.

Recently there was an outage in the area, and all router settings were messed up for people. My default gateway has been messed with, and when I type 'ipconfig /all' in CMD, my default gateway is set as '24.64.168.1', meaning there is no way to get into my router. Upon typing my router's default gateway IP to access the webpage, being 192.168.0.1, I simply get a 'page cannot be displayed' due to the fact that my router doesn't have a default gateway. My IPv4 address, which should be 192.168.0.1xx, is, for whatever reason, set to 24.64.171.99.

What I would like to do is manually set my router's gateway IP to 192.168.0.1, so I can access it from my computers properly. Only problem is, only way I know how to change the router's gateway IP is by using the router.

Here's my ipconfig info:

Windows IP Configuration

Host Name . . . . . . . . . . . . : Chooga
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : lb.shawcable.net

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : lb.shawcable.net
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : D4-3D-7E-91-E1-9C
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 24.64.171.99(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.252.0
Lease Obtained. . . . . . . . . . : Thursday, March 26, 2015 3:22:19 PM
Lease Expires . . . . . . . . . . : Thursday, March 26, 2015 4:24:53 PM
Default Gateway . . . . . . . . . : 24.64.168.1
DHCP Server . . . . . . . . . . . : 64.59.135.150
DNS Servers . . . . . . . . . . . : 64.59.135.133
64.59.128.120
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.lb.shawcable.net:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : lb.shawcable.net
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter 6TO4 Adapter:

Connection-specific DNS Suffix . : lb.shawcable.net
Description . . . . . . . . . . . : Microsoft 6to4 Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2002:1840:ab63::1840:ab63(Preferred)
Default Gateway . . . . . . . . . : 2002:c058:6301::c058:6301
DNS Servers . . . . . . . . . . . : 64.59.135.133
64.59.128.120
NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:9d38:6abd:34f3:317d:e7bf:549c(Pref
erred)
Link-local IPv6 Address . . . . . : fe80::34f3:317d:e7bf:549c%12(Preferred)
Default Gateway . . . . . . . . . :
NetBIOS over Tcpip. . . . . . . . : Disabled

To me, it seems as though it's simply going directly to shaw, and not properly handing out IP addresses.
This is beginning to become quite the bother. Can I get any help on this?