Inadequate Taxify App

I requested a ride from home to pavilion. The trip was supposed to charge between 80-100. However, the gps directed the driver to pinetown and then to pavilion, resulting in me being charged 135. When I disputed this charge to the driver he said it's the gps's fault and I should complain to taxify but must pay this ridiculous amount. I'm very disappointed and disgusted. why should I pay for the app's stupid mistake. I would like to get a refund.