VOX TELECOM worst cancelation ever

So, I phone Vox to tell them im very impressed with the service and would like to jump my line from Durbanville to Paarl. They still get the money I still get the fibre. Nope, i have to cancel. Okay. This is on the first Monday of a month the 2nd of March. One month notice right? Should end by end of march. Oh no they tell me I missed the month notice with a day and i HAVE TO PAY FOR APRIL too. Even tho I will not be using the service. R899 for nothing at all.