Claiming unpaid fees by a company due to its administrative error

Sir, Madam

I signed in Dec. 2017 a business contract for a short audit assignment with a local AD company. The CEO of the company requested my services but recently resigned.

The company paid the first payment on my private UAE account. But in Jan 2018, the finance department realised their mistake in the selection of contractors. They wanted a company and not a single entity.

As requested, I gave all documents required for a new vendor registration counter-signed by my local partner company. After delivery of the preliminary report, as per contract terms, they still didn't pay the 2nd payment for misalignment with the 1st beneficiary of the payment (me).

They have launched an internal audit. The company has not followed the procedure, nor reacted quickly on the affair and tried to cover their internal error.

What are my rights as an independent consultant not residing in the UAE? Can I file a legal case for the non-respect of payment & breach of contract? What is my/partner probability to win this case?