Collection of paid up account

I had an RCS Game card which due to some financial difficulties I ended up in arrears. I started getting collections calls non stop from VVM and I then made plans to pay off the account. I received an SMS with a discounted amount to pay. I paid the money via Internet banking with the assistance of the collections consultant on the phone. I then emailed proof of payment as requested and have been begging ever since for a paid up letter. as if that is not enough now there is vericredit who have started harassing me about the very same account. I sent them proof of payment and they sit for 3 months with no contact and when they get bored they start with the phone calls and SMS. I have paid off the account. Please update your systems and stop attacking me non stop!!