Paid a deposit to someone for a deal that fell through

What usually matters in this situation, and the papers to keep ready before you meet an advocate or free legal aid (call 15100).

Do these now

A dated list of every amount given and every amount repaid
Your advocate needs the exact balance claimed. Where: Your statements and notes.
Ask your advocate whether to send a written demand or a legal notice
A demand and the reply (or silence) can matter later. Where: —

Borrower's full name and current address
Needed for a notice or a case. Where: Your records.

Transfer records (statement, UPI history, cheque encashment) — Proves payment and the date.
Proof of where the cash came from (withdrawal slip or statement) and when it was handed over — Supports a cash loan.
Signed agreement or promissory note — The clearest proof of a loan.
Complete chat where they accept the debt or promise to repay — Shows the money was a loan and may affect time limits.
Records of any part-payments they made — Part-payment supports the loan and may affect time limits.
The original cheque and the bank's return memo — Needed for a cheque-bounce case.
The cheque (check its date) — Cheques are generally valid for 3 months from their date.
Names and contact details of people present — Can support an oral loan.
Your written demand and any reply — Their response may admit or dispute the debt.
Messages around the time of the payment (them asking for money, saying why they needed it, or promising to return it) — Without a signed paper, the surrounding messages often show the money was a loan and not a gift.

Time limits apply to money claims. A written acknowledgement or part-payment can affect them. Your advocate will check.

General information, not legal advice.