Uber poor service

I used an email link from uber to get my sixth ride free up to R80 off when I got to my destination the amount was still the same I paid with the card I sent 5emails to uber no reply since from the morning now R84 was deducted from my account even though I used an uber promotion which they sent to me this is poor service sending emails to say you get free rides when there isn't any I want my money back now