Despite huge investments in customer service resources and the awesome power of the X1 video platform, Comcast saw its score tumble 6% year over year in an American Customer Satisfaction Index (ACSI) ranking subscription television services.

Overall, the subscription TV category saw its score decline 1.5% to an average of 64, which is the same score as internet service providers.

Verizon Fios led the pay-TV sector once again, increasing its score 1% to 71. AT&T followed closely, with U-verse scoring 70 and DirecTV scoring 68 on the ACSI's 100-point customer satisfaction scale.

Altice’s Optimum system (formerly Cablevision) was the highest scoring cable operator, trailing Dish network (67) by just one point.

RELATED: Comcast customer satisfaction at highest point since 2001

Charter Communications came in at 63, up 5%, largely due to the customer service strength of its Bright House Networks acquisition.

Comcast, which has been chest-thumping its two-year-old $300 million customer service investment, as well as the user experience of its X1 video platform, saw its ranking score plunge to a next-to-last 58.

Mediacom, meanwhile, finished dead last, despite a 4% uptick to 56.

RELATED: Comcast, TWC drive major overall pay-TV improvements in ASCI customer satisfaction survey