Win 10 pc did not work when I tried it either !!

Tried Win 7 pc and straight in.

Can see no explanation for this. Neither can ZEN.

Turns out prblem I was having with ZEN FTTc was a BT issue.
They rebuilt something and link now works, only took 4 weeks.

Hello pcbbc,
I would give PlusNet a ring and make sure that the username you think is associated with your landline number still is..
I had a issue at a business where there are four lines all with PlusNet .. all of a sudden one line would not connect..
e.g. with location A, tel# 01234 111 111 router A (user A) NOK, location B, tel# 01234 222 222 router B (user B) OK.
No-one had done anything at the premises.
Rang PlusNet who said, vehemently, that "you've plugged router B into tel# 01234 111 111... I see user B trying to log in to tel# 01234 111 111.. and router A into tel# 01234 222 222"
"NO I HAVEN'T, THEY ARE 100yards APART AND HAVE BEEN AS THEY ARE FOR YEARS!" I retorted.
PlusNet resolved it by reallocating tel# 01234 222 222 to location A and tel# 01234 111 111 to location B.

Anyhoo after four days of no service, an OpenReach engineer called in "just to check" and it appeared that they had been "working" in the local exchange at the time things went doolally...