Spectacular Coloring, Sunburst Picotee Mix Begonia Bulb

I bought 3 different begonia bulbs. None of them have sprouted. Now the automated bot will not let me contact the seller about them.

I received a tiny little tuber with one extension (it was supposed to be a large tuber) that looked like growth but never took off. In fact it completely dried up and now it's too late to get my money back or order one to replace it. I did business with this outfit last year and had the same result. I should have known better.