I would not pay a thing, but I would have had a handyman change the cartridge or do whatever was necessary within 7-10 days.

They had me look at the panel & it was jimmied (with obvious signs of flashing) to allow excess current through all the circuits including the bypassed cartridge fuses. 

I would unscrew the cartridge retainer (with the water off) and see if there's any leftover part of a handle in there.AquaSource is indeed a Lowe's product.

Had to hire plumber to help replace handle cartridge.

Moen faucet, with replaceable cartridge.  

If a respirator is used, it needs to be tight fitting and equipped with P-100 cartridges.

I  have hard water in my area,  so I only buy cartridge style faucets.

If only one area is lower pressure on the cold side, replace the cartridge and blow the line out.

It turned out there were some issues with the shower valve dripping the cartridge.

I contacted the building management company and they mentioned  a pluming company which had done work in other units in the past.That company sent a plumber and it was determined that some of the shower cartridges were failing, so they needed to be replaced.