<human>: Can you condense the text into a few key points?

So a few weeks ago it came to my knowledge that I shouldn't have used 1040 to file my 2014 taxes, since I was in the US as a student (earned income through OPT). I'm now amending my 2014 taxes via 8843 + 1040X + 1040NR-EZ. 

**However...** a few weeks after I've filed my return (March 18, 2015), I received this mail from IRS (April 13, 2015):

> We received your Form 1040, federal individual income tax return, for the tax year listed above, but need more information to process the return. 
> 
> The letter you received provides two options to respond to this request: 
> 
>     (1) our secure website OR
> 
>     (2) a toll-free IRS telephone number
> 
> These options allow you to verify your identity and the IRS to continue processing your tax return.

I used their website to try and verify my identity but it didn't work, so I ended up going to the IRS office and sat down with a IRS staff. I handed over my student visa documents and my passport and the lady didn't say much, nor did she indicate that I filed using the wrong 1040. Fast forward to early May, I got a refund for ~$3.5k.

 

I've called a CPA that deals with NRA taxes, and he said since I got a ~$3.5k refund for 2014 and appeared in person at the IRS office, I should just leave it alone. Soooo should I file my 1040X for 2014 or just leave it alone and file it correctly this year?
<bot>: First time filing taxes, filed 1040 instead of 1040NR, went to IRS office for ID verify, got a good amount of $ back, CPA said no need to amend it.