Sold me a heater and vent kit to install for my client. They shipped without the vent kit, then shipped again a week later also without vent kit. Went weeks without resolution, then no effort to make right after having to buy the vent kit elsewhere at a higher cost to get hot water back in to the house using their heater which was already installed.
Do not expect a quick answer back on anything, do not expect them to make any attempt to make it right when they make mistakes.