Sudden relieving/ termination by the employer

I would like to get suggestion for future course of action. I was dismissed / relieved of my duties without any information. My login id was disabled from the backend ending my 13 years of service. There were no issue raised on my conduct ever in these 13 years, I was in free pool and was being asked to proceed on LOP for 3 months. While that was being discussed, I applied my available leaves and proceeded on leave. While being on leave HR disabled my id account. I came to know next day when i was not able to login. Is this legal and can i challenge the company in labour court. Though appointment letter does have a clause of relieving which is arbitrary. the offer letter has clause " This contract of employment is terminable, without reasons, by either party giving one month prior written notice during probationary period and two months prior written notice on confirmation. X reserves the right to pay or recover salary in lieu of notice period. Further, the Company may at its discretion relieve you from such date as it may deem fit even prior to the expiry of the notice period. However, if the management desires the employee to continue the employment during the notice period, the employee shall do so. Please confirm that the above terms are acceptable to you and that you accept the appointment by signing a copy of this letter of appointment.