How can I deal with job disputes?

I worked in state department 'A' for 3.5 years with outstanding record. But confirmation in service order was not issued even after successfully completing my 2 year probation period. In the meanwhile I was selected in govt.dept."B"of same state. So, I requested to get relieved from parent dept. They relieved me without mentioning about lien in relieving letter. In Dept."B", I was under training, when senior officer from dept. "A" asked me to technically resign job of dept."A". Treating it as technical resignation, I resigned from dept."A". Now I want to revert back to dept. "A". I have worked in Dept.’B’ for 2.5 years but have not been confirmed in the service of dept.’B’ yet. Because I was new in job ,so I thought mere relieving from Job in dept. "A" will maintain my lien in that dept. Moreover, senior officer of dept. "A" must be knowing the rules, they were also silent on service confirmation and maintaining my lien. In this scenario can I claim to go back to parent cadre I.e. dept. "A"?