taxify overcharged their clients

Taxify overcharged their clients, I have many examples like this and taxify are not clear on how they calculate the trip.

Example: Githuri Rd, Nairobi, Kenya at 08:58 to ICRAF Rd, Nairobi, Kenya, is a 5.5km trip. FARE BREAKDOWN Base fare 85.00 Distance 160.00 (30Ksh/km) Time 45.00 Total KES 290

Here is my return with less distance (5km instead of 5.5km) - same route Limuru Rd, Nairobi, Kenya, 18:25 to Githuri Rd, Nairobi, Kenya, 18:36 FARE BREAKDOWN Base fare 102.00 Distance 300.00 (60Ksh/km) Time 38.00 Agha Khan Hospital 50.00 (Parking at the hospital where I'd never been) Total KES 490

second example, for the same trip back - 5.5km United Nations Ave, Nairobi, Kenya, 18:36 to Githuri Rd, Nairobi, Kenya, 18:47 - 5.5km ARE BREAKDOWN Base fare 85.00 Distance 200.00 Time 35.00 Agha Khan Hospital 50.00 (Never been there) Total KES 370