BAD SERVICE FROM EDCON!! VERY DISAPPOINTING, IS THIS THE WAY YOU TREAT CLIENTS?

I have an account with Jet. I have had one since 2015 and have never missed a payment. I paid on the 31st of July. To my surprise i kept on receiving messages that they are putting my account on arrears due to failing to pay. I sent proof of paying to them several times , still they send SMS and Emails that i have a payment due which was not done. They even increased my premium of the payment to be due end of August. This is so disappointing and discouraging. I have never missed a payment ever in my life not even once ever since 2015. Is this the way to say Thank you to Loyal clients?????????????