I purchased 2 0520RLE air conditioners at cosco at the end of last season Sept. to replace my old units for this year. I opened them this year to install. One box has no hardware at all just the unit so I cannot install it. I took it back to cosco and was told because I purchased it over 3 months ago it was the responsibility of the manufacturer. The one I installed is great.I need all hardware including side panels. I only have the brand new unit. Please advise

Heating & Cooling - Daewoo - DWC-052C Air Conditioner