I am having the same issue here as well, I receive/send about 40-70 calls a day and in the morning missing about 15-20. so grouping numbers is very very important for me. But equaly important is flagging/marking them so I can tell at a glance that I have returned the call or not.
When I got my new phone which came with kitkat 4.4.2 I noticed that It was not doing many functions that it used to do before. Grouping numbers is one of my major ussues but as important is knowing at a glance that I have returned the call or not.
Calls not in my contact are always seperated now, and if I do call them back then original number presses is NOT updated/flagged as returned so when I have multiple numbers that are missed it forces me to remember the number and then proceed to the next number I need to call back, after about 4-5 numbers like this I have no choice to remove the number from the log manually because I cannot remember whom I called back or not or I have to compare it to the top of the list then scroll back down to the missed calls.
This is a major downgrade in productivity for me.
Also when I click a call from the missed log it does not even mark whom I called back!!! I have too click again to the ALL log to see if I did or not. ( DOES NOT MAKE ANY SENCE TO ME why they would downgrade this way )
The best soluton so far is get an app that deletes the missed call I called back. but what if I do not want it to be deleted because I MAY need to call them back? If sometimes happends to me because of my type of job.
It was perfect before as it made sense, If they are going to change it then at lease provide a way of giving the users a choice between simple and advanced.
I have Downloaded over 10 apps trying to get one that would solve this issue or bring back the functionality of previous versions but I dont think its possible because its in the core of the OS.
I am sure there must be a lot of people that use there phone for sales, or business purposes that must be just as frustrated as I with this ussue.
NOTE: I mentioned sales or business as if your getting just a few calls a day then this not really an issue but if your like me recieving and sending many calls and have had previous experience with the older version of the OS then you will certainlly see
my very valid and extreamly frustrating point.