How can I recover partial payment made through NEFT to college.

Sir, I bring under your notice that I've given a blank cheque to a private college for B.A.M.S degree course and given verbal instruction to produce a cheque after 10 days and he issued against that a bonafide certificate for admission in 1st year course year'16-17, but they have produced the cheque immediately and cheque got bounced. There after college has said, transfer the money through RTGS/NEFT within 10 days and They have confessed by mistake it has been produced to your bank. Initially I have transferred amount of Rs.50000/=out of Rs 2 lac to check whether it has been transferred or not?. when I inquired the same to the college authority then they said I have sold the same seat to others on higher donation and refused to give an admission, meanwhile, I opted for another college for the admission because the cut off date of admission was 15th November'16 and I got the opportunity to take the admission and then I have requested to return of payment but ignored. what should I do?