There is mistake in pronunciation!
Not: "c i", but "ci". This is one word so you should read this like one.
How could you?
Dlaczego w podpowiedzi jest: "believed"?
To forma czasu przeszłego, a więc jak najbardziej właściwa podpowiedź.
Wouldn't "Uwierzyłem ci!" mean "I believed you"? and "Wierzyłem ci!" mean "I was believing you!"?
Hmmm... "uwierzyłem" is more about the moment when I 'started believing', therefore rather "I believed you about something specific". (added now, by the way). "wierzyłem" is like "I used to believe you" (and it seems that now I don't).
"I have believed you" should be accepted, too. It implies that I've changed my mind recently or that I now know the truth.
Well, English is not my language, but would say : I believed in you. It was not accepted...
That's a different thing.
I believed you. - I believed that you were telling the truth.
I believed in you. - I believed that you would succeed.
In Polish, your sentence is "Wierzyłem w ciebie".