Firmware Update Help C7000v2

Have been on the phone for an entire day trying to resolve this... Purchased C7000v2 on 01/10/21 and have intermittent Internet along with very slow speeds since install. Netgear support  (3 calls and purchased additional service contract for $79.99) tells me that the firmware is old (V1.03.01) and that it needs to be updated to (V1.02.09) by my ISP (Charter/Spectrum). Spectrum (2 calls) tells me they cannot help me because it is not their equipment. WTF?

Other than returning this unit to Best Buy, what can I do to resolve this? Any help is greatly appreciated.

Thanks!