Vodacom needs to do their job properly

My husband had a vodacom month to month contract. He passed away in May 2019 and I submitted all the necessary documents to vodacom and they canceled his contract. A year later vodacom handed him over to vvm attorneys who constantly phone me every day 3 to 4 times a day asking to speak to him as his account was handed over by vodacom. I have e mailed all necessary documents to them a number of times and still they harass me. Vodacom are also still requesting documents and thus has already been sent. This has really upset me as it's more than a year later.