[Puzzle spoilers] For people wondering about the keypad: it's not on a phone, it's on a computer in the internet café. The passcode uses numbers which look like letters, just you might substitute in one of the many passwords we all need nowadays (e.g. pa55w0rd), or if you write words on a calculator as some commenters have said.
The phone is NOT BROKEN. If you can't use it then you haven't done the things you need to yet. Check around the carnival for clues or read earlier in the walkthrough.
The bucket of ink is not broken. If you can't use it then you've missed an object you need to pick up.
The walkthrough is not broken, it does tell you everything you need to do to complete the game!
I did the Stencylling so please don't bash robotJAM!
The Next button is there because it solved some technical problems and I prefer to advance the game at my own pace with the sense of trepidation that comes before each click than to passively watch a card playing cutscene or see a lot of cards dumped at once.
 "Harry Quantum 4: Doc Star"){kind=icon}
 "Harry Quantum 3 : Cheese Carnival"){kind=icon}
 "Contract"){kind=icon}