Telkom is the worst network!!!

I'm very disappointed with telkom, I bought R100 telkom airtime in April, I tried to load it and it expired, how can it expire so fast, what nonsense, I phoned the call center and they said I must go return it and ask for another voucher, how stupid is that why would the shop give another voucher. This is the 3rd time Im having this problem with the voucher being expired so fast, last year it happened twice and I ignored it, but not this time!!!! Other networks are not like this.