"They didn’t want to turn up. They haven’t got time for us in their busy schedule."
An episode featuring late contributor Cath aired on Wednesday.
The daytime star's errant phone caused chaos during an otherwise-very-serious panel discussion.
The Good Morning Britain presenter appeared in season eight’s The One Where Rachel Is Late in 2002.
"Did your inner thoughts come out on national television to millions there?" Susanna asked her Good Morning Britain co-host.
The former EastEnders star was not impressed with how she'd been described in an on-screen graphic.
The presenter said her former colleague had been "very supportive to me personally".
“Even I didn’t see that one coming!”