Company wants me to leave job but forcing me to serve 15 days notice period

I am happy that they want me to leave, i will get new opportunities. They told me, you have to leave with in 1 month, so i decided to find new job and got one after long time..new company want me to join with in 12 days.... Now current company want me to serve 15 days notice period, they are not ready to compromise... I dont want to loose new job... So what i can do, i am feeling depressed now. Things to consider : - i work as software developer (work from home) - they want me to leave because i am sharing knowledge on youtube that how to create softwares, they are worried that i am exposing their clients ideas to world and thats not the case.... I am creating everything by my own for tutorial, without using their assets - i have not signed any documents related to job, just received an appointment letter by email - no issue with payments, but they have not issued me single payment slips Please tell me, what if i serve 6 days notice period out of 15 and then leave current job without asking for permission, will i have to face any legal work for this, beacause they are forcing me to serve notice period and i dont want to leave new opportunity, plzz help