NHTSA Complaint #11576751 — 2017 KIA SEDONA

We noticed coolant leaking. We took it to a dealer and they replaced coolant control assembly/ temperature control piece. Also the O-ring that connecting to the engine was leaking. However, this is the 2nd time we are replacing the piece in 3months (not the o-ring). We did that. And spent $900 on it. As soon as we drove it 11miles home, there was oil and coolant leaking again. Took it right back. And there was fluid in the engine. Guy believes it's the head gasket. Out car isn't running. We don't know if we should replace, or junk it and have a loss of money. We are so frustrated. We have 125,000 miles. There were no warnings, no lights, just us noticing the coolant leaking, and the reservoir being full. We have pictures and have taken it to multiple mechanics and dealers.