- Open Listings → My Listings and press Edit.
- Find Primary Category.
- Choose the new one and save.
The categories offered depend on the listing type. If the category you want is missing, your listing type is probably wrong — change that first.
If the category you want is not listed
The list is filtered by the listing type you chose at step 1. Change the type first and the right categories appear. A mosque listed as a Business is shown business categories.
After changing it
You move onto different browse pages, so views may shift over the following weeks. Check Analytics after a fortnight rather than judging it the next day.
Only the primary category changes. Tags and services stay as they were.