Unfortunately ISP tech support is more and more tailored to the common calls - which includes a large number of Joe Public who use the terms WiFi and broadband interchangeably. And more likely than not don't have any network cables in the house.
The number of posts in local facebook groups asking a whole community "Is anybody elses wifi down?" with no other detail never ceases to amaze me...
As a plus point, at least in this case it was all network related - which is better than the time someone at VM tried to convince me the wifi on my non-VM router was making their TV box forget channels...