Missing Payment Amount from Credit card

I made a payment recently to my credit card, but the payment is not reflecting. I have mailed *** numerous times since last week and also phoned. With no feedback within the 72hours from the email and the customer service agent telling me the 72hours was not yet over in Friday. Now I can't pay my credit card and I will also incur additional interest rate cost. This is poor service and I am not even sure when my payment will reflect. I would like to have this sorted out.