Highly disappointed

FNB warning. Do not book any flight or car rental or infact any purchases in your FNB app, they quick to approve purchases and take the money but then you don't get the service you paid for! Then they give you a run around to try and reverse their mess ups. I was traveling from Joburg with my family and our car broke down in Ladysmith. On the 24th of December we rented a car from Avis using my FNB app to get home, FNB app showed availability and ALLOWED the payment to go off, once we got to Avis they told us they have no cars available and I have to call FNB to reverse it (I then had to book a private taxi from Ladysmith to KZN, meaning i paid for a rental and paid for a private taxi which costed more than the rental). FNB sent me a form to fill out for the reversal, I filled this form on the 24 of December and sent it through, they then told me I need proof from Avis and I got it and sent the email AGAIN TWICE. It's is now the 17th of January, I over spent my budget already paying for the rental and then I had to break it even further and hire a private taxi, thanks to FNBs great mess up I had to pay double the rental amount to now get a private taxi. Since we sent the forms we been trying to call FNB and sort it out. A 100 calls later and speaking to 100 diff departments I'm still not sorted out! How can this be ethical for such a big bank? You guys messed up my family's festive and now we going into the newyear still fyting. I left capitec where their service was on point and no 100 day waiting period to get assisted or speaking to 100 people not knowing what's going on. I really thought I left my previous bank for better. I am highly disappointed in FNB!