Capfin debit mandate approval doesnt work on weekends

I have been a loyal costumer for more than a year now and I don't want to lie I haven't had any problem with capfin until today. I app**** for a loan and they sent me a debit mandate approval which I approve instantly only to be called and told that my bank didn't approve but am wondering how come because I did approve it in time. How am I expected to wait a TAT of 7 working days when I urgently need the loan. I am wondering if maybe this whole approval debit mandate thing doesn't work on weekends cause if it doesn't should we be informed about this. I am so disappointed .