RCS payment Queenspark

The people who handle the Queenspark RCS accounts are unsifisient and rude. I have paid my installment for my March account on the 26 of March with the same reference as all the other months, the keep on sending me messages stating that my account is in arrears you can't get to speak to a person to sort it out, you get to speak to a call center that is un helpful and useless. I have been faxing through proof of payment to a centralized email address with no reply ?