Poor communication

When I returned their car and i explained I had a flat Tyre but went to the garage and it was fixed. I was given a form to fill just to say in writing what had happened to the tyre, and all was fine then left. Two day after I got my invoice via email and saw I was billed for refueling yet I had refueled less that 500m from drop off. I let that go. Another two days passes then I call their customer service to ask when the refund will be available on my account and I was told there was a claim being processed of the damaged tyre I had signed for and I told them I'm disputing that claim, when I wrote down what had happened it was not explained that I was signing for them to claim for new tyre otherwise I would have refused until I had spoken to management about it and I was told only the branch manager of east london airport branch cn assist. The call centre agent said she'll send an email to the branch manager to contact me. I called the branch over 20 times on different numbers over 3 days and their line is never answered. I sent an email via the site and still no feedback from europcar. This is really frustrating. What an unprofessional way of helping clients. As for your branches landline not working is beyond.