Slow Satellite Internet Service

Since switching from Verizon DSL to Dish Network as my ISP, my browsing/download speeds have decreased dramatically, despite my measured download speeds (via testmy.net and speakeasy.net) having increased from 6-7 mb/s to 16-21 mbs (!) since the change. I have made no hardware or software changes here, but web pages now load painfully slowly, images in e-mail messages are delayed, etc. Dish Network responds to my complaints by citing "ping latency" and the distance to the satellite, but my calculations (round trip of around 45,000 miles at 186,000 mi/sec comes out to around .25 seconds) don't bear that theory out.

How do I remedy this situation, or convince Dish Network to fix it?.