Billing me even though I cancelled the contract

I tried cancelling my account with Webafrica on the 24th April as I'm moving. I've received an invoice for June which they won't cancel or credit. Below are some of the responses I have received from their customer care agents: Agent 1 - Rep**** asking to confirm the cancelling of a different address to the one on my invoice/account Agent 2 - Told me I can only cancel my account if I return their router because i'm cancelling under 12 months (I've been with them since 2014, had fiber since Jan 2017) Agent 3 - Told me I can't cancel my account as they already have a cancellation request sent through on the 3rd June 2018 (the future)