Bad service, incorrect invoicing

I'm told I changed my billing cycle, and I never I just paid on the 28th,consultant are very inpatient, unable to explain billing cycle, cause now I pay on the 25th now it says 1st I never changed it I don't know what happened, I just made payment on the 28th as I change accounts, can this be fixed as I am billed pro rata so what I used for September I pay on the 25tv October but now it shows I must again please can someone view my statement and how I am billed and fox this, I pay every month on the 25th I have never missed a payment on this account, I am very irritated by nokulunga whom just sounded and said it is what it is, sometimes you become a client, you don't to prove a client that you are the best