Unless changes to the controller programming have been made, you should be able to increase the top speed of your bike to about 25mph with no expense or new parts - just see this video, or any of dozens of other similar ones, for the simple hidden-menu access to do it:
https://www.youtube.com/watch?v=KEGRkhP4aeYPretty much all of us with the 35A controller upgrade seem delighted with it; mine pushes my Mini ST2 up hills it couldn't handle before, but it will NOT increase your top speed beyond about 25mph (nor will a motor swap in most cases) - it roughly doubles available power to the motor, adds acceleration, torque, more performance/tuning options and a couple features including cruise control. I bought my kit from Bolton (now Area 13) but it's the same product as ElectroBikeWorld, just pick the one with the best price at the moment. If you order from EBW, make sure you also order the new display as well; the stock display won't work with that controller.
Here is a useful, but Chinglish, manual for it with many more details:
https://www.emotoer.com/wp-content/uploads/2020/03/KT-LCD8H.pdfAnd here is a pretty good video walkthrough of the new menus to cover what's in the manual:
https://www.youtube.com/watch?v=y_NEXdUCOiYBelow is a table of my current settings, which should be a pretty good starting place for yours since the bikes are similar - the "Jim4" column is my current setup, but you can also see my previous experiments and settings from EBW, Bolton and others on this forum I used as a starting point.
If I were you, I'd return that motor immediately for a refund, if you can.
Cheers!