Uber India — difference in final price after trip ends

Address:

560066

There are two incident with me where uber showed me less price while booking the cab and when the trip ended they charge more money and i noticed that whenever they offer any promo offer it happens
Incident 1 :
I took a trip on 10 aug from my house (Hope farm) to sbc railway station initial price was 325 while booking the cab but when the trip ended it reached to 496.55. I couldn't do anything as they don't have any support on call or in the app.
Incident 2 :
I took a trip on 19 aug from bengaluru arirport to my house (Hope farm) initial price was 743 while booking the cab but when the trip ended it reached to 838.06. I couldn't do anything as they don't have any support on call or in the app.
This is how they are looting people first show they the promo code so initial price will be less and when the trip ends increase the final price

Ps: when i saw the invoice for both the trips all the increase amount was there in surcharge category and also i noticed whenever you use promo code this type of price increase happens otherwise in normal trip price remains the same.