For our upcoming trip (October) I've already had to modify our homebound itinerary twice and we still have 4 months to go. Originally were flying home to SMF (Sacramento) via IAH (Houston) and upon checking our itinerary about 6 weeks ago I found our layover in IAH had been cut to 10 minutes. Even I know that won't work. Called United and rebooked via Denver with a 90 minute layover. Was very happy with the change as it got us home about 2 hrs earlier than original. Three weeks later I check our itinerary and what do I find? Now our layover in Denver is cut to 21 minutes. This time I call United and ask for a supervisor in an attempt to get an upgrade to economy plus (5 extra inches of legroom). I don't think that's too much to ask. First person I speak to won't connect me to a supervisor, but rebooks us through IAH (Houston again), but now we have to leave MCO a couple of hours earlier. The next day I call United again and eventually get a supervisor and explain the situation and I'm told I need to address my concerns via the United website link to customer service. Gee, can we make this any less personal??? I compose a lengthy message to United about not only this trip but past trips when we've actually had to change days we flew. Several days later I get a phone call from United, but as we weren't home they didn't leave a message on the answering machine. I call them and explain the situation and the guy I talk to gets us our upgrade, but not until he's gone out of his way to tell me that he's "going out on a limb" by giving us an upgrade. Wow...I'm impressed! I'm relatively sure I'll have to go through this at least one more time before October. The other thing that really chaps my a$$ about all this is that not once did United notify me of the changes. I had to check my itinerary to find that a change had been made. Now that's customer service!!!!!!!!!!!!!!!!!!!!