Hammand pole and vodacom

I had an account which was handed over and now paid with hammondpole I received a letter to confirm all of this but now I am receiving threaten and sms that I still owe. This is after I asked several times if all is clear and is there any catch. They advised that all is well. I even asked to rate their services as wonderful only to be met by sms a month later that read"There are still outstanding fees due to HP Attorneys from a recently settled account Call: *** or WhatsApp *** for more information" I do not complain but this defeated me mentally and emotionally.