This is how your money moves from your bank account to the mutual fund companies:
Money gets debited from your savings account > Your bank sends it to the RBI registered payment partners > Payment partners segregate the money and send it to the respective mutual fund companies (their bank accounts).
It may sometimes happen that after you make a payment, the money gets deducted from your bank account, but it does not reflect on Niyo. Usually what happens in such cases is that the bank debits your account, but due to network issues at the time of making the transfer, the money gets stuck at the bank's end (does not reach the payment partners).
In such cases, the money generally gets auto-refunded to you in upto 10 working days by the bank. There is nothing to be done by you and you don’t need to worry at all. If you have additional money, then you can make the payment again after some time.