Why was my EMI not debited from my bank account?

It might be a technical issue or a minor delay. Just for reassurance, you can contact the customer care at your bank to check your account status.
Or, it could be that your bank account did not have sufficient funds.
In such cases, you can login to your Mihuru homepage and pay your instalment. Please keep in mind that any delays in payment will attract a late payment fee, unless such delay was due to a technical issue beyond your control.