I doubt very much it was your timer, it is rated at 15amps and you are well below that.

The only thing I can suggest is to call HTG explain what happened, but I would tell them I am a rare orchid breeder and if you do not get a new ballast by tomarrow morning, you will stand to lose your crop or at least severly damage it. My gut feeling is they will do there best to help you. They do not need the negitive plublicity so it is in there best intrest to help you.

let us now how it turns out,

Also they give a one year warrentee on the ballast so I doubt they are trying to sell crap. With electronics occasionally stuff like this happens, so hopefully you unfortunatlly you got the one bad apple in the bushel. I have the same ballast bought around the same time.