I updated my twitter app on iPhone 4s, and now its not sending me push notifications?

[Chanel]

Help guys, i really do not know what to do. Basically, i updated the old twitter app for the new one. And now its not sending me push notifications, so i don't know when i've got a new tweet or a new DM. Instead i have to go on the app and refresh it to see if i have a new mention. I called apple tech and they went through the basics like, checking everything's on in the notification center. As well as doing a hard reset. Thats all they could do without me having to pay 21 pounds.
I'm at a loss of what to do, there nothing more annoying than technical failures, and i use twitter alot. Its pretty irritating; having to go all the way onto twitter just to see if someone has replied me. If any of you have experienced the same problem and sorted it out, please tell me what i could do to find a soloution,

Thankyou.

[TheMagic_NRG]

Go to the notifications section in settings, then scroll through apps you have until you see twitter, than push ON.