getting error while redirecting my website form http to https. i already tryied all htaccess methods.

hey all, i need some help regarding my domain redirects. i tried all htaccess methods to redirect my domain from http to https with www but nothing happned. also A Valid SSL is installed with domain. i contacted hosting provider company but they are not able to resolve my problem. Note : i am hided my page extension form all pages of my url. and also a wordpress blog installed with same url which is . . when i want to login my blog by url/wp-admin it shows 404 page because of htaccess code and then if i remove my https redirect code from htaccess page it opend but that time my main page of my urls is shows broken. kindly help me or reply this thread if any possibilities available. thanks