Getting more speed

Thought id ask the brains trust!

So i made the plunge into e-bikes and bought an on sale e-bike from a local retailer. It’s a 250w rear hub bafang motor, and a G51 Thunder display. I haven’t been able to look at the controller as it’s hidden in the frame and I’ve not had the motivation to unscrew the battery terminals to get in.

The original display was password locked and the retailer refused to give me the pin, so i bought the same display on aliexpress and hooked it up thinking that i would be able to alter the settings for a higher top speed, as its currently limited to 25kph but no dice, the motor cuts out at 25 regardless.

Any ideas on what i can do?