Problem regarding free trial subsctription cancellation

I joined free trial of IMDb pro using my debit card. But 3 days ago I got a mail form IMDb stating 'We hope you are enjoying your free trial of IMDbPro. Our records show that the authorization for your credit card was denied. To ensure uninterrupted access to IMDbPro.com, please check your Discover credit card we have on file'.
Now I'm unable to continue pro account and also can't open account setting. Only page appearing is renew your IMDB pro account.

"We appreciate your prompt response to this matter. If your card is not updated within 3 days, your free trial will be cancelled and you will be charged immediately upon renewal. If you have any questions, please contact us." 
This was also writen in the mail. 

I want to ask would I be charged automatically from this card in future days as I don't want to continue with IMDb pro and want to remove my card from it.

Please suggest me solution to this.