How does the UPI payment option at Zerodha work?

This is one of the drawbacks I had to face, when using UPI for retail online transaction.

The money goes out of the BUYER’s account but does not reach the SELLER’s Account. The transaction gets failed somewhere in between.

The Buyer who is not aware of this, then thinks the seller has got it, but does not want to dispatch the item, This then raises un-necessary dispute between the buyer and seller for no reason.

It takes about 2 weeks for the BUYER to get the money automatically refunded to their account.

Meanwhile the BUYER is left with no cash in bank.

@Matti When Transferring cash to Trading account, is there a chance this could happen ?

Or meanwhile, is it much safer to use the existing fail safe methods, like NEFT, IMPS ?