Double billed for a device they collected

I tried to upgrade my contract online and though the order showed as placed I didn't receive a confirmation email. A few days later I called Vodacom's customer care. The agent confirmed that there were was no upgrade processed for me. A few days later I received 2 devices on separate days.

After a week of back and forth with vodacom they finally processed a collection for the extra device to be collected. 2 weeks passed and the device was STILL not collected. I called back in and after a lengthy amount of time on the phone and several calls back, another collection was arranged.

Within a day, the device was collected. I however am still being double billed because vodacom claims they never received the device their courier RAM came to collect.

I have since spent hours trying to get this resolved and see no light in sight.