Harassment for Payment

I received my Woolworths store card statement on the 15th of Feb by email. <br> <br> According to the statement that I received from, my installment is due by 7th March 2016, however, I paid my installment yesterday morning by EFT.<br> <br> 3 hours later I received an email from the WFS Nation wide recovery services, demanding that I make payment immediately, and contact them to make arrangements. Needless to say this is extremnely duistressing, as I had already made the EFT payment 2 weeks BEFORE it was due!. <br> I emailed them, explaining that this payment has already been made, and asking for them to contact me to resolve the issue. <br> <br> Yesterday afternoon I received a call from WFS demanding payment on my store account. I told the operator that this has already been paid, by EFT - 2 weeks before the due date on my statement. She did not seem to understand, and kept asking me when I was going to make payment.<br> <br> Is this how Woolworths treats their loyal customers??<br> <br> I demand an apology, and assuarnce & written proof that this is not going to reflect on my ITC score - as I am definately not at fault.