Amending Avios booking...UTTER FAIL!!!

I booked a car and paid in full with Avios points (12450). Pick-up 3'rd June, drop-off 9'th June at King Shaka.<br> <br> Missed my flight to Durban, so that evening via Avis website I attempted to modify my existing, paid for car hire booking to now collect on morning of 4'th June. Only reason I did it online as phone number for *** went straight to system voice mail at 7:30PM. Anyways...Avis system instead of modifying existing paid for in full booking creates a brand new booking for 106Euros!<br> <br> Next day upon collection, I explain to the nice lady at front desk at King Shaka that there are 2 bookings on the system now. She brings up both bookings, says not to worry she will cancel the duplicate booking and process everything under the original Avios booking. Great, what service!<br> <br> Now I receive a charge of R1731.04. AVIS charged me for the damn second booking!!!<br> <br> I've now spent 90 minutes bouncing between 4 separate AVIS departments and drafting emails with pictures of my account. A lovely lady Thulisile is helping but come one guys, this is pathetic.<br> <br> Please refund my money soonest (minus petrol charges).<br> <br> Regards,<br> Jared