Show Cause Notice For Freelance Work

Hi, I have been working for a company for last 5 years and for some financial problem i had started
my freelance work from home last year.
When i submitted my resignation latter to company on 14 march 2014, then my boss called up and
request me to stay one month more. after 10 days my boss called me up and told me that they have
issued a show course notice to me at my address. but i did not get any notice. when i went to office
they asked me to sign the show cause notice at office.
I refuses to sign. I really dont know what to do now.
Plz give me some good answer.

Dear Kaifee,
you have not maintioned the main things, that, on what ground they have issued the show cause notice,..? if they have send you the show cause notice, so, they must have send it through register post AD. So, they must have the acknowledge of the same..? if you have not signed any of such postal letter, then dont worry.
as i said, let us know the reason of show cause notice, so memeber can guide you properly.

Hello Tushar,
Thank you very much for your kind answer. Actually my brother work freelancer and for some reason i asked my brother to withdraw all the amount in my account. They have seen my bank statement and now they are questioning me that why i work freelancer.
First time they told me that they had sent me the notice and you have received it on 2nd april but they lied to me. I never get any notice and they were putting pressure on me to receive the notice in office and accept the fault. But i did not accept and sing the notice in the office. Next day they sent me a mail in which they have attached a screenshot of the mail thats shows that i have received the notice on 5 . Its all started when i submitted my resignation letter.
Plz guide me..What they want actually.

Dear Kaifee,
Good to see some more lights on this matter & got easy to understand, kindly refere the below points.
1) How did they dare to check your account statement..? its confidencial part.. .
2) if you have worked as freelance while you are the employees..? then its your fault.. but subject to terms & condition of your employment letter.
3) Your resignation letter is dated on 14th March & Notice send by them on 2nd April (If they send you), so, notice send you post your resignation, so, it can be treated as null & Void.
You should ask them the acknowledge copy of notice received by you.. its give you the clear pict. about it.