Telkom landline

I have an account with Telkom landline adsl uncapped, I relocated to the Northern Cape on the 27th but before relocating I went to Telkom at East gate to notify them and to please cancel my account because the are I'm moving to has no network, I was given reference number and told it would be cancelled, and then today I receive an invoice saying I have to pay for the month of march!! I will notpay for it because I'm not even using their services, I have even trying to call 10210 for the past 3weeks and they are always experiencing high call volumes always wait for minimum 15min waiting to be connected to an agent!! It's frustrating so I never get thru because it always exhausts my airtime , pls assist in closing my account , but in definitely not paying for this month because I requested to close and it was not done