Conditional CASE Statement (Domo)

I've run multiple searches both her on Stack OverFlow as well as with Google and have not found anything that helps with this question. We're trying to determine the number of customers that have to call more than a certain number of times in order to have their concern/issue resolved, i.e. those who are not able to receive first call resolution.

Domo obviously can determine the number of times a certain phone# has called in, and we've generated a card using the funnel graph but we're having trouble finding a way to filter / exclude customer phone#'s that have called less than a certain number of times (generally 2x or less), and on the flip side isolate those who have had to call in excessively, i.e. OVER a certain predetermined number of times which would exclude partner lines we don't need to review.

Multiple CustomerPhoneNumber occurrences (Funnel Graph image)

Single CustomerPhoneNumber occurrences (Funnel Graph image)

Not sure if this helps but the following are various "attempts" at a Beast Mode that may help to better visualize what we're trying to accomplish; don't actually want to count CustomerPhoneNumber occurrences that are =<2 or >50 since the goal is to exclude them from the Funnel Graph being used but we can't find how to do this with existing card filters and figured it would require a Beast Mode calculation:

(CASE WHEN COUNT(DISTINCT CustomerPhoneNumber) =< 2 OR >50 THEN 0 ELSE COUNT(DISTINCT CustomerPhoneNumber) END)

(CASE WHEN COUNT(DISTINCT CustomerPhoneNumber) >2 AND <50 THEN COUNT(DISTINCT CustomerPhoneNumber) ELSE '0' END)

(CASE WHEN COUNT(DISTINCT CustomerPhoneNumber) >2 and <50 THEN COUNT(DISTINCT CustomerPhoneNumber) ELSE '0' END)

(CASE WHEN COUNT(DISTINCT CustomerPhoneNumber) >2 and <50 ELSE '0' END)

COUNT(DISTINCT CustomerPhoneNumber) >2 and <50

Obviously, none of these are working nor do they validate in Domo - thanks in advance for any assistance...