George Russell claimed "the punishment doesn't fit the crime" on Sunday after being handed a late drive-through penalty because his Mercedes team had bungled an earlier five-second fine at the Monaco Grand Prix.
The 28-year-old Briton, the pre-season favourite for the drivers' title, said the heavy sanctions had resulted in him falling from third to 14th and missing out on a points finish as he also slipped from second to third in championship.
He was given a five-second penalty for speeding in the pit lane when he made his first pit-stop, as were seven other drivers during a race punctuated by stoppages won with by teammate in Italian teenager Kimi Antonelli.
"Firstly, I'm not too sure why we got a penalty because I was on the pit limiter before the line," he said.
"I released it after the line, but clearly there's a problem in the software and many drivers got penalties.
"Five seconds... not ideal, but not the end of the world. Then in the pit stops, there was major confusion and (I end up) getting a drive-through. The punishment doesn't fit the crime. P3 down to P14."
He said he went to appeal to the stewards in person during a late race suspension, but was told: "Rules are the rules, if you don't serve the penalty it's a drive-through. I don't really know what to say. It's two races in a row.
"I could have won the race last week, could have maybe had P3 or P4 today. That's 40 points down the drain for things outside my control."
He added: "I probably gained 0.1 of a second in the pit lane with that software glitch, but ended up losing 12 seconds because of it."
His Mercedes team boss Toto Wolff said: "One part of me feels so happy for Kimi, but the look on George's face... He had a weekend that was not good, so I need to keep it balanced emotionally and pick the team up going to Barcelona.
"This (Monaco) has often been a bogey track for us. The last time we won here was 2019."
He was full of praise after seeing what Antonelli was capable of doing under intense pressure.
"He has the control, he's quicker than anybody else, he does the re-starts and he builds a gap... It's unbelievable."