Handed over within 3 weeks (blacklisted)

I was handed over for cancellation Vodacom sent me the message that the outstanding usage will be billed on this month's billing cost. It's not even 4 weeks since the communication was sent our telephonic agreement was the 25th of June yet I woke with an SMS from their attorneys stating that I must contact them or further legal action will be taken against me..

How is that possible? Tempering with one's credit profile why couldn't they contact me if they felt they can't wait for the date which we agreed on last month?

The attorney consultant revealed that a lot of Vodacom customers are complaining about the way you handle them..

Can someone please attend to this ASAP please.