What do you have access to?
Because yes, you'll need to modify the .htaccess again to tell Apache not to force HTTPS.
That said, I would say, if you couldn't find a way to access and modify the .htaccess to add the HTTPS forcing rule, then you can modify it again. How do you deploy the modification of the htaccess. (I try to know more about the setup for give you more help)
I don’t know, maybe SSH access? To the file system?
If you can access maybe try this htaccess :
Options -Indexes
RewriteEngine On
# Redirect from deskflex.com to staging.zenapay.com
RewriteCond %{HTTP_HOST} ^deskflex.com [NC]
RewriteRule ^(.*)$ https://www.staging.zenapay.com/$1 [L,R=301]
# IF request HTTP, redirect to staging.zenapay.com in HTTP
RewriteCond %{SERVER_PORT} 80
RewriteCond %{HTTP_HOST} ^(www\.)?staging.zenapay\.com [NC]
RewriteRule ^(.*)$ http://www.staging.zenapay.com/$1 [R,L]
# IF request HTTPS, redirect to staging.zenapay.com in HTTPS
RewriteCond %{SERVER_PORT} 443
RewriteCond %{HTTP_HOST} ^(www\.)?staging.zenapay\.com [NC]
RewriteRule ^(.*)$ https://www.staging.zenapay.com/$1 [R,L]