Incorrect Billing

In February I spoke to a consultant telephonically to inform them I'll be cancelling and not renewing both my contacts in March and April respectfully. Tje lady confirmed that she's noted it on the system and I don't have to call again. To my surprise I receive an invoice of R100 billed for the month of May. I queried it and waa told the 2nd contract was not cancelled. The debit order of R100 didn't go off from account as usual on tje 25th but went off on the 1st of June. I then receive an invoice last week stating that I'll be billed R302 for the month of June. How when the debit order went through from my account?

I'm quite irate of this incompetence.