Make them do what they don't like to do. That usually means bringing them up to the net on your terms. Once at the net you can pass or lob them depending on their skillset and yours. Short angle shots are also an option.
With serving, always think of body serves. Pushers tend not to like being forced and this may give you midcourt returns you can attack.
When receiving most pushers have no strong serve or they wouldn't rely on defense only. Try stepping in on their serve before they begin their motion so that they can clearly see you standing well inside the baseline to attack. If they are really weak on the serve, I've seen players standing a foot behind the service line as a challenge and it can rattle a server.
While in the heat of the struggle, I'd keep trying new things. Find one weakness and attack it relentlessly. As a group, pushers are risk-averse and mentally strongest when frustrating their opponent. You need to frustrate them. For instance, if they have an iffy low backhand since pushers tend to play well behind the baseline, keep going to it with angle and backspin. Isolate their weakness and focus on it.
As a proviso: If they are good at handling all of these things then they just might be better than you and your options may decline down to learning from your loss.
