Fairphone support is currently taking a long time to reply to support requests (they’re working on improving this). They are occasionally on the forum, but support requests do still need to go through the support pages. To avoid confusion: the community moderators are not Fairphone staff. See also the welcome banner:
If I recall correctly, if you ordered your phone in October or November you should have received an e-mail about the phone shipping with a different cover. See the post below (click the title to expand). If this applies to you then you should receive a code to order the cover of your choice sometime this month.
Unfortunately I’m not aware of any topics that have any hints that are helpful to your call problem, but maybe somebody else can still help out.