He started off with 150 channels and they took 20 away and added 12 so he has 150-20+12 = <<150-20+12=142>>142 channels
He called and asked to reduce his 142 channels by 10 channels and added 8 sports channels so he now has 142-10+8 = <<142-10+8=140>>140 channels
He ordered the wrong sports package and the new one adds an additional 7 channels for a total of 140+7 = <<140+7=147>>147 channels
#### 147