Resignation in 7 months - company asked my new company to pay the visa cost - what can i do as per UAE LAW?

Dear Sir/Mam, I really need your advice. I didn't complete my contract in my company, and now i resigned and still 7 months work.
So my company asked my new company to pay the visa cost if not i need to bear the visa cost
And then i asked my manager for 20 days, he dont want to signed and give back my resignation letter because he just give me 30 days notice only
Please let me know what can i do as per UAE LAW

Hi,

Before completing the contract period you are switching over to other Company @ Middle East and hence current employer demanding for visa cost incurred for you by them. Please check your employment terms and follow the separation clause as mentioned in your offer/appointment letter. Also it is not clear whether you are in Tourist Visa or work Visa. As per my knowledge some companies recruit the candidate bring them on Tourist visa and then will move them to work visa Better consult a local Employment Legal Advisor and take a call. As Middle East rules are very much stringent please make a cautious move else they might restrict your future entry into Middle East itself.