Airtime disappear due to service error my fault

I have been a loyal Vodacom customer for years. I am however highly disappointed and this is why. I had to buy a new data bundle, mine was low. So I loaded R165 airtime to buy 1gig data for R149 - something I do once a month cause as a single mother of a 6 month old times are tough. I try 3 times to buy a bundle, getting error msgs every time. Try again before I go to bed and I only have R113 left. So I can't buy 1 gig. Where did my airtime go?? Next morning talk to helpful vodacom consultant that tells me there was indeed a service error but they can do nothing about my missing airtime. It is because of their service error I couldn't buy my data, not because i did something wrong. I had to settle and buy 500mb for R100 - completely ridiculous! I expect this matter to be sorted and be refunded my missing airtime - no, be refunded with 1 gig data. I would very much like to continue being a loyal vodacom customer