Ola — Charged double for one way trip

Booked ola roundway pune Mumbai Pune..fare shown 3350 .. reached mumbai..driver charged 3759 for one way saying u have clicked wrong time slot.. totally unfair.. I have always been ola fan.. safe and frndly rides..but am really shocked for this high fare..I have always travelled with fare[protected] one way..how can u guys charge double amount? Tried calling customer care..waited for 10 minutes on call but no response.. I want refund of my hard earned money.. u guys shud be considerate with the time slot thing.. how can u guys keep 4 hr slot if it's practically impossible to come and go in this minimum time...
Plz do sumthn..or else I will lose all from trust from ola.. Ola is supposed to be economic ride but this high price is really not done ..
Distressed ola customer