Blaming Weather But Was Mechanical
 

Delta is blaming the weather when it was announced as mechanical failure and are now trying to charge me $100 to reschedule. Plus, I used miles, and they want me to pay the difference between miles to rebook this flight. But it's not my fault, and Delta won't take responsibility. They suck, and I will never use them again if it is at all possible. Their customer service representatives spoke broken english and were rude. They were obstinate and very unwilling to help.

I think we need more details here. Even if your delay/cancellation was due to weather you should have been re-booked without additional fees and without requiring additional miles. What were the circumstances?