Not acknowledging releaving mail

Hi Team, In my current company X, i am being hired for a project suppose P1 which is mentioned in Aggrrement that I am hired for the particular project but after few days they have been aligned me for another project P2 in different roll which is done by verbally and without informing me the criteria of project P2. I was doing there ( but eligibility of project is not matching and letter has been issue by clinet that need to replace, So I was searching for job and got an opportunity with immediate joining with in 10 days in Y company. In the time X company offered me another roll but I denied. So, I have resigned. As per offer letter, I have to serve one month notice which is mentioned in the offer and no. Pay off option in offer letter. However, I discussed will the concern person and he told, you have to pay complete month salary. I agreed to pay and want releaving acceptance. I haven't disclosed to X that I get an opportunity in X company. All this things, I haven't mentioned reason of resignation. I simply resigned as thahks for the offer but I am looking for technical job. Please accept my resignation and in my second mail I aggred to pay 1month salary. But still not getting any reply /acknowledgment.