Milesource has raised the Gift certificate redemption levels:

There is no more $150 GC.
For a $ 100 GC you need 11,500 miles(was 9,000)
For a $ 75 GC you need 9,000 miles(was 7,500)
For a $ 50 GC you need 6,000 miles(was 5,500)
For a $ 25 GC you need 3,500 miles(was 3,500)

By the way, somebody posted in this forum that Milesource denied redemption in some cases. Is this problen still existent?
Or did you succeed eventually?