orange to plusnet switch lost wifi

[#1]

Recently switched from Orange to plusnet. I have a siemens router Gigaset SE 572, that allows broadband connection but I can't now connect to the internet using my iphone, getting an error message unable to connect to network "orange...." as given on the back of the router.
Any help would be appreciated.

[#2]

Having the same problem but on o2 going round in circles!! (DLink Router)
dick:quote

[#3]

Hi
managed to sort problem by re-setting network setting on the phone ( check out youtube). Reinserted router password and wi-fi worked fine.
Hope this helps anyone else that has the same problem.

[#4]

Probably would, if you gave the YouTube link  !