So everyone who says they are "cured" is lying?
No.
They are simply bisexual, in denial, or both. Think about it. If you were in such an environment as a place that promised to "pray away the gay", and everyone was pushing you to not be gay, and the entirety of your experiences when facing your homosexuality resulted in those same people calling you a fag, then what do you think they would do?
They force themselves toward heterosexuality in attempt to appease and fit in with those around them, and appease the christian god.
Peer pressure and fears of a man in the sky who hates them for what they are.