Help regarding Labour Card

Hi guys...
I am working in Qatar under husband's sponsorship. I have resigned my 1st job and joined a new company. While resigning I submitted my labour card to the old company. Now for making my new labour card, my company is asking to get my resignation letter signed and stamped by the previous company. When I asked them about the same my old company said they will give sign and stamp only if I submit my new Offer Letter, Company CR and Authorized Signatory's id copy. Now I want to know is it really required to submit these documents to my previous co to get my resignations stamped by them? Actually my old labour card is expiring on 10th Nov 2015. Please advise!!!
I am not changing to a new sponsor. I am under family visa only. I have resigned 5 months ago after giving 1 month notice and is working with the new company for 3 months. Now why would my old company ask for these details.
Yes, a serious and responsible sponsor will only release you if he gets the details of your new sponsor. He wants to know that you are safe.