FNB lies

I loaded airtime from my fnb banking app but never received it. I spoke to my service provider and they said the error is on the banks side. So I contacted fnb and received a response that they will investigate and get back to me. After a few days I get an email from them that they spoke to the service provider and the service provider said the airtime was loaded successfully thank you and goodbye. So I phoned my service provider again as I still dont have the airtime, and the service provider said it was not loaded and they have no history of this transaction so I must call the bank. How can FNB outright lie just so they dont have to refund??? I was always so proud of fnb..... I think its time to take my business to another bank