Poor service at Metrofibre

Its been 2 months and half month been a customer and so far l have experienced the worst service ever. They fail to send invoices on time, want payment and proof of payment. After sending a proof of payment several times,they don't correct the account. Later send an email that there's been discrepancy on the account and it's been correct. Then debit the same amount that was paid a month ago and say it is mistake. To hell with the useless apologies for poor service and ignoring to resolve complaints.

I want my refund immediately for unnecessary double biling.