My nam is Veselin Vasilev and I am a private re-taxi

Good Morning. My nam is Veselin Vasilev and I am a private hire-taxi driver(uber) in Bristol. I had an isue vith client. The rider requested me fev nights ago and when I droped nim and his gilfrend to there home he droped his phone in the back seat. I picked one more ckient after him and after i droped the second client i found the phone. After few minutes the phone rang and I answered. Was same client who lost it. I said to him that I am far now and will return the phone later or if he pay me the fee(£20) will return it ASAP. He said that he is happy to pay the fee and want the phone immediately. I went back to his address and showed him the phone. After he see the phone he said that he refused to pay me the fee and said that this is the phone of his gilfrend. I desided to keep the phone and bring it to the office and I said to him. After that he tryed to catch me through the openet window I was scared of his attac and drove away. After work I reported for the lost phone in the office. Next day (Sunday) the pollica came to my house and take the phone and said that I drove over client's thumb. I was surpised and I dont know what to do in situaton like this becouse he hurt himsawes in result of his attack against me. Can you give me adwise please. Thanks