Comcast says it's impossible to bridge Ciena 170-3916-904 copper ports.

LONG story short: I'm trying to minimize points of failure and bottlenecks, avoid using a 1-off small switch, and connect 2 separate L3 devices to each copper interface of a Ciena delivery switch. Comcast claims those ports can't be bridged for use in the same WAN IP block. Comcast claims that each fiber circuit only works with a single copper interface. I have no experience with this model but also find it hard to believe what Comcast says. I'm waiting on a response from my friend that works at Ciena, too. Any help is appreciated. It took 3 months for Comcast to get fiber (Metro Eth) service working at one of my client's 3 locations. Comcast still can't figure out why 2/3 locations aren't working.