CellC greedy sharks

We subscribed to CellC for our fibre internet connection almost 2 years ago. They installed the internet free of charge as long as we signed a contract that stated we would pay them for the installation fee if we cancelled early. I was busy packing and moving house and did not have time to research the precise dates. I did it now and we were a mere 8 days short of being done with the 24month contract. CellC debited my account with R4261 now a month later. Should they not have been obliged to inform me that If I wait 8 days I won't have to pay so much?