Why are Medicare Advantage premiums going up almost 300% in NC?

I have a fairly liberal co-worker who is on Medicare and just got notice that his Medicare Advantage premiums are skyrocketing in 2015, along with his "out-of-pocket" costs, his deductibles and co-pays. He received an email from AHIP claiming this is all the result of the ACA, and that these premiums will continue their dizzying upward ascent in the years to come.

Now I know AHIP is skeezy group, but what is the deal with these increases? They are WAY out of line from what I would expect, but I am not an expert on Medicare and its various programs. This particular plan is sold by Blue Cross of NC, and the increases are:

Monthly Premium: $18.90 increasing to $64.40
Out of Pocket: $3,400 increasing to $4,500
Doctor's Visits: $10.00 increasing to $20.00
Specialists: $35.00 increasing to $40.00
In-Patient Stays: $170 increasing to $250

What is going on here? Is the ACA causing these hikes or is there another explanation?