My account was locked when I changed the payment card and now is there a way to get it back ? 
Hey @0E .
Thanks for reaching out.
I am sorry to hear about the trouble with logging into your Shopify account! Did you happen to check your admin email address to see if Shopify has attempted to contact you about this? I would suggest checking your spam/junk folder to see if it may have landed there.
Since we cannot authenticate you for the store in question using the Community forums, I am unable to look into the specifics of account. WIth that being said, in order to get further assistance it would be best to login to your store using our Contact Us page. This will allow us to securely verify you as the store owner.
If you are unable to login, you can select the option to Continue without logging in. Once you successfully login or select the option to continue without logging in, you will be directed to the Help Center - type in what you would like assistance with in the search bar to locate the option to Get Support under the search results. This will allow you to reach out to our support channels to speak directly with a Support Advisor about the situation.
Let us know if you have any questions.