Unauthorized Smartphone Purchase on My Vodafone Bill

On May 3rd, 2023, I discovered that an unknown person had purchased a smartphone through the installment payment option on my Vodafone bill. I am very unhappy with Vodafone's response, especially given that I did not make this purchase. Vodafone has shown no interest in resolving this issue despite my efforts, complaints, and even the writing of a formal letter. Despite my protests, complaints, and even the writing of an official letter. I've never been even one day late on my bills, and I've kept a high level of loyalty points over the years. The existence of such a system is beyond comprehension. I have an urgent request that Vodafone, as a corporate entity, take immediate action to resolve this matter.