All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
If the company where you are training had conditioned on you to work for it for a period of a year and a half after training, and you mentioned that they are paying you a salary in return for this condition and they have not benefited anything from you yet, then it is not permissible for you to fail to abide with the condition which they conditioned on you. Allaah Says (what means): {O you who have believed, fulfil [all] contracts}[Quran 5:1]. Furthermore, the Prophet said: ''The Muslims should fulfil their conditions.'' [Abu Daawood and At-Tirmithi]
As regards what you mentioned about the whispers of the devil, then this is just one form of his enmity to you in this world and in the Hereafter. Allaah Says (what means): {Verily Satan is an enemy to you: so treat him as an enemy. He only invites his adherents, that they may become companions of the Blazing Fire.}[Quran 35:6].
Finally, if you do not want to fulfil the conditions, then you are obliged to return to the company all the salary which you received from them without benefiting them in return.
Allaah Knows best.