There are three different ways you can reach out to Customer Support: Email, Web, or In-Game.

Email

Email us directly at msf-support@scopely.com
WebGo to https://marvelstrikeforce.com/, then tap the small bubble at the bottom-left of the site and start a conversation.
In-Game
  1. Tap on the "Settings" icon in the upper right side of the screen
  2. Scroll down in the Options window and tap on the "Support" button
  3. Tap the bubble located on the top right side of the screen and start a new conversation