Can the employer ask the employee to pay visa expenses upon finishing contract?

My two-year contract will expire in July 2021, and I resigned in January with a six-month notice period, as required by company policy.

However, after I’ve sent the resignation letter, they've asked me to pay for my visa. They told me I needed to work for at least 5 years to cover all of the recruiting costs, which was sadly stipulated in my employment contract.

As per my knowledge, employers are not permitted to reimburse any recruitment/visa expenses from employees. Furthermore, I will complete my 2 years contract so why do I need to pay it.