First, let me tell you, I don't know, exactly, what MCA is ... but from your question, it appears that it could be some Certificate of Accountancy, which Involves, IT, meaning, working on the Computers ...
Neverthe less, the fact is, that you are doing it ... and ... now, midway, you realize, that MCA is not the thing you would like to "do" for the rest of your life.
That You would rather be an Executive, Giving Orders.
So I ask you ... Did someone ask you to do MCA, or was it your own Choice, and who is Funding your studies ?
If, it is your family elders, who have asked you to do MCA, and funding your study, I suggest, you Trust their Choice ... and do MCA ...
But if you are Self-Financing your studies, then make the best of what you have Spent on your Study so far.
Your idea of Post MCA, MBA ... is a good idea. IT/Computers/Ledgers, will however, remain the Major, in your MBA.
We don't usually get, what we like. This is a Fact of Life.
Therefore, it is in your best interest, to pay full attention and work hard for your MCA ... get good grades, and then do your MBA from a good University.