Can someone explain this?

Okay, so I know that I am not the most experienced TFT player in the world but I know the basics. I know the comps, their strength and weakness, etc. Now, I am pretty uncertain though. I happened to build a mage - ocean - summoner - warden comp in a game and got shit on by a glacial - poison comp. Next game I built a 6 glacial - berseker - poison combo with singed and ezreal. Ezreal had multishot, sword breaker and spear, my warwick was lvl3 with iceborn. I got totally destroyed by a mage - summoner - inferno - ocean comp. My opponent had pretty much the same comp I had in the previous game just weaker since he had only 3 mages while I had 6 when I lost. He didn't have a single golden unit or any good item. My 6 glacial with poison should have utterly destroyed him tbh. Yet he survived with 5 units with full hp. I didn't miss what happened i just couldn't comprehend it. His lvl2 zyra had no items at all, yet she one-shot my lvl2 ezreal. One cast of plants and my ezreal died. I played some inferno myself and I never ever dealt this much damage with lvl1 inferno trait, not even close. Her next round of plants killed my lvl2 mundo and so forth. My whole army got one-shot and I have no idea how. I sent a report, so Riot will check it hopefully. it was fishy as hell that much I can tell. However, I am open to hear reasonable explanations if someone has it and willing to share, so I can learn from it. [slayer-jinx-catface]