How does Karma works? Will happen same with me the way I had build my bad Karma?
e.g If I've stolen money then will I face same, will someone steal my money?
Or do I've to pay more than that?
Karma is dependent on:


intensity of your volition and number of thoughts involving the action
purity of the subject of the action


So if you seal from a very good person the the karma will be strong likewise you take time to execute with a lot of effort and /or you feel very strongly overcome by greed then this will cause more strong Karma.

Now to overcome this Karma if you make a donation the same apply. In this case the motivation is not strongly rooted in greedlessness hence Karma may be week. Hence giving many time over what you stole may not defunct this Karma. 

Also note your roots of good are generally weaker than roots of good. This again means unwholesome action (stealing) and counteraction (donation) in the balance of probability might be heavier.

All this is balance of probability. There are rare cases where people who have done a loot of good and little bad have got bad results and people who have done a loot of bad and little good have got very good results, hence this is also a motivator to get out of the cycle of birth than accumulating Karma may it be good or bad. Whenever you face a situation alway try your level best to accumulate good karma and not the bad though. 

Also if you perceive someone to be good to do something against them you need stronger volition regardless of the person being good or bad. Also you repent and regret the action more increasing your Karma. Regardless of the level of volition of perception if a person is good he is like a mirror. If you steal from such a person the Karma will be greater.

Also see: The Working of Kamma, 2nd ed, by Ven. Pa Auk Tawya Sayadaw