Charged with no service provided

Vodacom fibre, my router stopped working and I decided to cancel the contract, the customer agents in the cancellation department logged a fault to fix the problem with my connection because I must give a month's notice, I received a call from the 1st line agents to try and troubleshoot the problem which could not be fixed because it was a hardware issue. The fault was never attended to after I spoke to the 1st line agent and the submission for cancellation was logged, towards the end of February they debited the account even though I was not connected due to the hardware fault. Vodacom wants to debit my account again even though I'm in the 2nd month with a fibre line that is not working because they never fixed the hardware fault. This is ridiculous!