• Paid cheque bounce, when I claim, false accusation of lost cheque

Dear Sir,

I am a software engineer, Due to some dependencies and money crises, I was looking for some consultant kind of work out side, to do part time kind of things. 
Last year October I from one my friends brother regarding a e-commerce website to develop. I understand all requirement from them, and I know this very expensive to develop, I quoted a minimum amount of 3lack, but they bargain and tried to put emotional pressure (Tomorrow we want to see you on board as CTO, money not matter, create relation...) to start work only in 1.5 L. Day night I work for them, As they ware not technical guy, I tried to help all kind of technical help to start company, which was not part of my job. even I designed logo for them. 
Some resource was need to buy online, for that they don't have Credit card, they told me to use my credit card, we will pay everything. 
They expecting to deliver in one month, which was not possible for a person or a IT company, I took 4-5 months, finally they published in one event. But they got different reviews about the website. I have designed same in front of them, but after that event, they told me that you made like this, that, you need to change, but that was huge change , which was not fit in that budget. I told them, I can't those things beyond that, and went to a company to fix those problem on to of that. 

Initially, both side we agreed to pay my Credit card bill, and my cost of effort, once they will publish, but asked them many times for my payment, but they show different cause and delaying again and again. Finally I forced them to meet and ask for payment. Went to a Coffee shop, there they given me 2 checks with post dated of corporate current account. But the amount for my cost of effort was not whole amount, they decided that, I have completed only 70% and they paid like that. That also I accepted, I was going through very critical situations.

I dropped first check to bank on given and it got bounced, I called them many time after that, they was not picking call, no response at all, wait for 2 weeks, again tried to call them, no response. I tried to drop again same check, again bounced. After that I called to my friend through whom they got my contact ask, where are they. 

After 3 weeks, I got call from that company guys, We need help on website, I told them, first pay then I will do. They sweetly told me , don't relate money to project. definitely we will pay, we waiting fro investors, next week you will get your all payments.

Wait for again 3 weeks, and tried call them, no response. I sent a mail to them that, please pay my bill as soon as possible, otherwise I will take legal action. In response, they written which was unbelievable.

Added so many false accusation, false story, false statistics and saying for me they lost 9 core market. Also added "2 checks are lost, and you put numbers, trying to withdraw from current account, better you return those checks otherwise we will take legal action on you".  

What to do now, I m a ordinary software engineer, from Odisha, they are local people. I worked for them honestly, day night, I used my credit card for them of 90k, but they doing like this, even not paying my credit card bill, for which I m paying interest.

Please help, thanks