R500 - R750 missing on my account

In Feb 2017 I changed my Vodacom contract from a Flexi 500 to a Smart M+ on the phone with a Vodacom agent and got the new handset by mail. Since April 2017 I try to find out where the R500-750 went that were on my account before I moved contracts - with a flexi 500 you can choose if you want this money converted to airtime or Data.

When calling Vodacom I was told that with moving contracts I automatically agree that I forfeit this amount however I never verbally or in writing agreed to that and it was not explained to me that this would happen. I said I would disagree and that I request that this money gets paid back to me or that I would get some kind of voucher or anything for it.

When I called in to follow up (about 15 times) one of the following happened: - I was told I would be called back, then a) I was never called back or b) the phone rang once and when I picked up the line was dead or c) I received an SMS that my query is resolved

I will not extend my contract with them if they don't get back to me, I am a client since 2005. I am incredibly fed up. One of the last reference numbers were 339853ISD and 1- ********** **********

What annoys me the most is that they are clearly trying to tire you out so that you eventually give up. What a bad client service, bad experience. They clearly have become too big and don't care about individuals.