I have a 30,000 BTU ventless Heater and need to have repaired. what or wh?

Where should I take trhe ventless space heater that I have for repairs. Ith Serial number is
RT0233166
Model # RTN300TP
30,000 BTU
I have tried to contact thr right delpartment but for some reason I could not get the right department.
The heater pilot light shuts off every time heater is on and I have to re-light it. Also the blower motor is not working.