The right to complain against a client company for abusing their right to sue

My partner and I are now residents of the UK but while we were in the UAE, there was a company-to-company deal signed with a client.

In between the completion of the contract, our company was transferred to someone else in the UAE. This person continued to honor the contract with the client.

But now the client is pursuing a personal legal case of misrepresentation in the UK against us, saying we misrepresented facts to their employee and got them to sign the contract.

We are mentally & monetarily being harassed by the client. My questions are:

What kind of counteraction in the UAE could we take against them for threatening us with legal proceedings and harassing us without any legal reasons and despite the contract not having any clauses against which we did the deal?

Also, is there mental harassment recognized in the UAE courts?