Dyson V15 Detect Not Working After Service - Refund Request Issue

I have been having problems with my Dyson V15 Detect vacuum cleaner for a long time. Because of these ongoing issues, I sent the device to service on 20 November from. After staying in service for about 15 days, the vacuum was returned to me, but this time it did not work at all. In other words, the product that was allegedly repaired came back completely unusable. During this process, Dyson customer service was very indifferent. They did not answer the phones properly, they did not show any interest in my problem, and they did not offer any concrete solution. Although my device had both warranty and insurance and the warranty only expired on 8 December, my problem was not resolved and the product was sent back to me in a non-working condition. My service record number is Z5S-EU-TGB7884A. In addition to the standard warranty, I also purchased a paid 1+3 year device protection insurance package by paying extra, but despite this extended protection, I still did not receive any effective support or solution. Given that my Dyson V15 Detect was faulty for a long time, did not get properly repaired despite being in service for 15 days, and was returned completely non-functional, I have lost my trust in the product and the service process. I request a full refund for the device. I ask for this complaint to be urgently reviewed and for my refund to be processed without further delay.