Don’t book through flight network

Was booking on cheap flights. Chose a date. The process confirmed my name, my contact details but did not confirm the date of booking. When I put my card details in, it went straight through without confirming the date. When the booking confirmation came in it jumped the date with a month. Tried to cancel the transaction but the telephone operator didn’t really understand me!!! It is costing me over 60% of the ticket to change or try to move