Try to fire my florist five months before wedding, and she requires i pay the full price

I’m trying to fire my florist because:
She started to ignore my email immediately after the booking (I only sent to her twice)

Initially committed to sending the design within one month, but it took over two months to receive any progress. No design progress was made until the day before our scheduled call.
Arrived fifteen minutes late for the call, until I text her.
Took five days to reply to my second email, ignoring some of my questions entirely. The promised vessel inventory list was never provided.
Assured a design change after our call but never did. Another two months have passed without any progress.
As the contract, I should pay the full price if I cancel the service. The payment will be charged automatically on the due date. Yes I did read the contract before signing, but this is the last thing I would expect. What should I do? Should I take any legal action?