Uber - Cape Town

I am unable to raise you telephonically and my private messages, go unanswered. My profile says I owe R26.00 for a previous trip! Would you please be so kind, as to give me details?? The only time I did not pay, your driver did not have change. The very next trip I duly paid for the current trip, the outstanding trip and your driver was tipped, on the two rides together. Please explain why, I must pay for a trip, already paid for?? My details: Email - ******x Cell - ****** Not that I am holding my breath but, I look forward to hearing from you.