Request for Monthly Usage Limit with No Response

I am currently subscribed to the paid plan for OpenAI API and have requested an increase in my monthly usage limit from $120 to $600. However, I have not received any response from OpenAI for over a month. I am wondering if anyone else has experienced this and how long it usually takes for OpenAI to approve such requests. Could you please advise me on whom I should contact for further assistance?

Thank you in advance.