phone booked in but no record and news of it

I took my phone into Vodacom Customer Care about almost 6 weeks ago and when I went to enquire about it, they could not track it. I unfortunately lost the slip during a car accident and cos of that I was told that I needed to IMEI number to try and track it. I tried calling the customer care centre a thousand times and the number is always engaged so I have no idea where is my phone. I did not even receive a sms to state that my phone was booked in or what is the problem with it...really tired of the bad service from Vodacom especially when you are a loyal customer and have numerous contracts with, everything seems to be a hassle with them!!