I doubt if your argument that no training is provided by the authorities. Also you mentioned that you would leave next year in middle. So by that time they would give you some sort of experience. Also do not forget that there are on-the-job training as well where they allow you to do the job and the cost they are bearing to train you in this manner is the opportunity cost. What i mean to say is obviously if you are new to doing this job, your time consumed would be more than an experienced one. hence work done is less considerably.
Although bonds are not legal in India, if you clearly read, it mentions that any bonded labor is illegal, this is in labor laws. and you are not a labor, you a skilled employee who is hired to perform skilled work and would be provided training and expected to generate results. Hence, a person leaving a job and breaking the bond is liable to pay at least the training cost quoted on your bond.
Thirdly, agreed that they might not have given you the whole of training as you said. But never forget Time is Money. They have wasted their time and efforts in recruiting you and then giving you time to adjust and perform on the job. The time is not going to come back to them. It would not have bothered if you would have rejected the offer even after the final selection process, as you have a right to accept or reject. But once you accept offer letter and then also sign a service bond you become liable for your duties and responsibility. You might put in your papers and resign in a month's time, however, the bank is not going to get a substitute in that period.
Just a piece of advice and nothing against you personally -
One needs to understand the fact that no matter how many degrees you have, unless you have a formal and professional experience, you cannot prosper. Just to give you an idea of the work culture these days, The Babu culture of strict 9-5 jobs have gone long back. People work beyond the actual office time; and no overtime is paid as now the work is shifted from time based to target and goal based. Finish your targets early and leave early or wait. Even the IT sectors, there are females who stay in the office for a couple of days when the project has to be submitted and deadlines draw nearer. When you seek equal working opportunitites you cannot also wish for discounting hours just coz you'r a female.
Either you make yourself very clear the next interview you give & inform them about your time constrains, or accept it and change your perceptions. One needs to change and modify the perceptions with changing time.