Absolutely disgusted

My phone froze and turned off. Would not turn on or charge at all. I had video and photographic proof of this happening. Sent the phone to Xiaomi for repairs. After THREE WEEKS they told me they were unable to replicate the fault so they could do nothing. The service I received was useless. What company makes someone hand in their phone for three weeks, only to tell them nothing is wrong with the phone, even when you have proof of it breaking???