Cellc payments

So i went in for an early upgrade, i was told to ppay an amount of R100 on my account and it will take 24hours to refelct and then i can do my upgrade. I did my payment and 24hours later i am told by cellc they can see my payment but it will take another 24hours to be allcoated once it is allocated a credit check will be done and only if i pass i am eligible for an upgrade.. This is poor service how can all the agents tell me they see they payment but i have to wait another 24 hours before my account is updated, should this not update te once the payment reflects? The reason for a payment to be allocated taking 24hours because sometimes they are busy and then they cant allocate.