Recovering of expense and salary

Dear sir/madam, i am working for a company from last 6 months (25th may 2015). on the time of appointment i promised to get rs 30,000/- per month and after 3 months of probation period the salary will increase rs 3,000/- per month which didn't increased. but after working for 3 month suddenly the business development manager of the company suddenly asked me if you want to work further then i can only pay rs 25,000/- per month and within 1 day you have to decide whether you want to continue or not. without any option i had to accept his deal, because within 1 day i could not have find out a job. i went to bangalore in may to attend an exhibition on may 2015 on behalf of my company where i spent around rs 28,000/- from which still rs 19,000/- is pending. i went on 5th of august 2015 to chennai to attend an exhibition on behalf of my company where i spent around rs 17,000/- from which still rs12,000/- is pending. on 17th of august the business development manager suddenly asked me to leave the company by 22nd of august with giving me only 6 days of notice period, where it has been mentioned on offer letter that 1 month notice period i will get. and today on 20th aug they forcing me and insisting me to give the resignation without paying my expenses which are pending from last 4 months. i have submitted all the supporting's. now they blocked my official mail i'd without informing me, threatening not to give the salary for the month of august 2015 and asking not to come office from tomorrow which is 21st august 2015. i am totally harassed and don't know what to do. because i supposed to get around rs 50,000/-. can you please suggest me what to do?