Do not take credit with them! Worst Customer Service ever!

I cannot believe how unprofessional this company is, I have paid up my account with you but every single day I receive calls and SMS's for debt collection companies to say that my account will be handed over if I don't pay. I have send numerous proof payments and requested that my account be updated. Nothing has been done, this negatively affects my credit score as it shows that I have an account in arrears while I have paid.