Dr Batra's — Refund of Hair gro

Yesterday have visited the clinic for hair treatment but now am feeling like being cheated as i have approved for payment of internal treatment cost was 16000 and have asked them that i will pay Gro Hair charges after 15 days after reviewing the results of internal treatment. But my husband gave them credit card for payment they 29000 rs
When i came back home all are scolding me what can i do when i called them to refund my 13500 amount they are denying

Pls pls refund my 13500rs which you have deducted for gro hair treatment
Will definitely pay if i found good results with internal treatment