Vodacom *****s airtime

I have 3 contracts whereby I pay either R55pm or R110pm and this same amount is credited back in airtime.<br> On 31 Dec at about 3pm I checked my balance to find that I had approx. R34 left. At about 2am on 01 Jan I checked again to ensure that the monthly amount of R110 had be credited to find that the total balance was just R110. What happened to the R34 that should have been carried over? I called customer service at about 2.30am but after about 13 mins the call was answered and immediately cut. Called again today and after 25 mins was still on hold. If they do not operate on public holidays they should say and not pretend delay is caused by high call voulume. I had noticed airtime disappearing previously and assumed that this was caused by phantom calls being made as the dial lock was not engaged that is proved not to be the case. In September over R350 disappeared and again I assumed that the phone was not locked. The phone was not used for 4 months as the user was in Europe and using a local sim card. I checked airtime on my other phone this morning to see if it had been recharged overnight which it had including the amount carried over from December. Vodacom pls explain.