Tata Mutual Fund — reversal after amount deduction from bank and units allotment

Address:

Visakhapatnam, Andhra Pradesh, 531001

Sir My folio no is 4544631/39 which is an SIP started from 07 Sep 18 and installment date is 19th of every month. On 19 Sep 18 an amount of Rs.500 was auto debited from my bank Account as 1st installment for which they even sent a statement stating 3.477 units at Nav 143.7965 were allotted in my folio on 22 Sep 18. Till 17 Oct 18 it was showing in my online account but suddenly from 18 Oct 18 it was showing zero units in my folio for which when I queried Tata mutual fund customer care on 23 Oct 18 their response was that the amount was reversed on 16 Oct 18 and it will take some time to credit. When I asked them why they reversed my amount their reply was very odd that the amount was not credited in their account. My 1st question is how can they reverse the amount which was not credited in their account? And 2nd one why it has taken so much of time from 19 Sep 18 to 16 Oct 18 to reverse a certain amount?? My 3rd one why it was happened that after allotment o[censored]nits and deducting amount from my bank account started a reversal of amount process??? Finally sir please make sure that this reversal process should stopped and my reduced units to be added in my account