Never ending harassment even after paying their client

If only there were a zero rating , I would rate VVM Legal , zero. I was handed over by a municipality in September. Upon calling VVM legal to arrange the payment, they told me that they did not have my case number/ ID number in their files. I then paid the municipality directly. I have explained this and sent proof of payment and my municipality statement countless times but they wont stop harassing me, they send smses, emails and call using different numbers. VVM, I will not pay twice because of your incompetence.