No feedback received payments missing

I phoned on the 2nd of March requesting an outstanding amount on my account to see if I could settle the account. The settlement amount given did not include the payment that was made on the 20th of February. I requested a statement just to find out that the payments for May 2014,November 2014 and February 2015 was not displaying. I had to phone Jeanette back after a week just to receive the reply that they are investigating. Today is the 13th of April more than a month has passed and still I have not received any reply or proof that my account has been rectified. I get constant sms`s after I made my payment to remind me to pay after I send proof of payment directly to Jeanette which is never read as I do not received a read reply back. I have not missed one payment since the arrangement has been made and therefore I see the way I have been treated as unfair and unjust.