It may be possible to get faster service. Quite a few people have downgraded to dialup then upgraded to dsl service on ATM which allows for faster service.
The only change with it is after dsl is disconnected, the line is changed from the frame relay equipment to ATM equipment which can get faster service.
It may be possible to call up VADI and have them change it from frame relay to ATM based dsl, which could be quicker.