Complaint sub-issue: Credit card company isn't resolving a dispute about a purchase on your statement

Summary : I purchased a custom XXXX XXXX laptop for {$2000.00} through Best Buy on my Best Buy credit card. The computer has a documented trail of regularly occurring fatal errors that XXXX technical support has not been able to resolve. I requested a replacement - which was denied - so I disputed the charge with Citi Bank who manages the Best Buy credit card. Because I did not return the laptop within 15 days of purchase, the dispute was denied and Citi Bank claims I am still liable for the {$2000.00} in charges. 

Timeline : XX/XX/XXXX : Initial purchase of custom XXXX XXXX laptop at Best Buy in XXXX CA XX/XX/XXXX : Email confirmation that order has shipped ( order # XXXX ) XX/XX/XXXX : Computer picked up from shippers warehouse XX/XX/XXXX XX/XX/XXXX : Intermittent fatal errors ( Blue Screens of Death BSOD ). Tried uninstalling and reinstalling certain software during these periods while falling back on two other reliable computers for work/school. 
XX/XX/XXXX : First formal request for support from XXXX Tech Support. Incident number XXXX XX/XX/XXXX : Second formal request for support from XXXX Tech Support. Incident number XXXX XX/XX/XXXX : Billing dispute filed XX/XX/XXXX : Billing dispute denied via telephone call Additional Details : It seems extremely unrealistic to me that the consumer should be able to determine in a fifteen day window whether or not they should return the merchandise rather than investigate resolutions independently. I chose the latter believing that if I updated the software drivers, uninstalled/reinstalled software applications, etc. that I would eventually find a solution and save myself the time required of returning and waiting for a new unit to be built and shipped. I also have two other computers at home that I use for work and personal matters. This XXXX XXXX laptop was designed specifically for my schooling and travel. It is extremely thin, light weight, portable, and powerful. As a result, it was used an estimated 15-20 hours over the six month timeline described above. All that I have asked for during all of this is a working version of the laptop I purchased. XXXX offered to send a technician to my home during working hours, Monday Friday to replace what they believe to be a faulty hard drive. I rejected this resolution as it would require me to take a paid day off from work and wait for a technician with no guarantee that it would solve the problem. It also by definition would mean that I paid {$2000.00} for a custom laptop that is now considered refurbished since the machine would have been opened and had faulty parts replaced. My request to Citi Bank and XXXX simply asked that a new unit be shipped, and in turn, I would ship the faulty unit back to XXXX. This would not only allow XXXX to prove that the unit I received was an exception, but also save XXXX the trouble and resources required of sending a tech to my home, and save me the paid time off required to meet the tech. When XXXX receives the faulty unit, they can run a more thorough diagnostic, replace any faulty hardware, and resell the unit in refurbished status. This seems to be a win-win scenario for everyone. Anything less than a complete replacement or a refund would be unacceptable by most standards.