Unwarranted and unfounded legal action - Hammond Pole Attorneys

I have received various emails from Hammond Pole attorneys informing me I have been handed over by Vodacom with reference HP ********** and account I ********** . I contacted Vodacom who said my account does not exist. I contacted the attorneys and asked for proof the amount is due, but they do not provide this. they then email me a week later telling me to make arrangements to pay my Vodacom account. I then responded on 22 May 2019 saying I will take legal action again them if they do not provide m with proof of the amount due, on which they responded on 28 May 2019 saying they will get me the proof. Nothing happened since then. I then received another email on 12 June 2019 saying i must make arrangements to pay my outstanding account. And still i have received no proof that i owe money to Vodacom. I have not had a vodacom account for 5 years.