I didn't understand your sentence. When a vacancy appears, do you (1) want the company to be told about you, or (2) do you want to be told about the vacancy? Which party do you want to be informed? "Refer" just isn't the best word here. You can find a way to fix it, but it would really be better to use a more appropriate word. Here are possibilities, depending on what you mean to say: (1) Please suggest my name as a possibility if you hear there is a vacancy. (2) Please tell me if you hear of a vacancy.

If you want to be referred to a company as a possible employee. You can say, "Please refer me to the company if there are any vacancies that I am suitable for."

"Please refer back to me if you hear about any suitable vacancies." You used the word "refer" correctly,but I have corrected the sentence for you. Send me a message if you have any other questions.