“There were grade discrepancies between your original application and the official transcripts received. Misrepresentation.”
It sounds to me like what the college is saying is that your reported GPA at the time of application and/or courseload didn’t match your high-school transcript. They are, in essence, accusing you of lying.
I’d suggest you triple-check your application-especially the section where you list courses, senior year courseload, and your GPA-to make sure it matches your high-school transcript as it was when you applied. If there was an unforeseen change to your transcript (dropped a class, grade revised, etc) contact your guidance counselor immediately and ask him/her to call the university and explain.
I’d also suggest you call the university and ask them for the exact reason you got this letter-I could be misreading that sentence.
As for the GPA below 3, I don’t know the details of your situation, but that could well be a more intractable issue. I hope that isn’t the case. Best of luck.