Hindustan Petroleum Corporation [HPCL] — online fraudulent activity

I paid rupees 350 through the google pay app as per directed by the hp refuel app. Even though the transaction was successful in the google pay app, the amount was not credited to my hp refuel account. On contacting the hp help line they assured that this was a technical error and the money will be credited within 24 hours. After 24 hours the money was neither credited or refunded and they are not answering the helpline.