StashFin — loan reimbursed was less than what promised

Address: New Delhi, Delhi, 110034

I had taken medical loan in january 2019 i had been given lesser amount then what promised by around 34000/-

I was promised the balance amount will be given within 15 days but it’s been 10 months no amount was refunded and above that representive stopped taking my calls

I don’t whom should i approach as i don’t have the number and their official email ids

Please help