Electricity bill from my landlord

Hi everybody, that’s my first post here on the subreddit… I really need help with that because even tho im living in germany since 2 years i don’t have the possibility to read documents properly. Basically today i received a message from my landlord saying that i got beyond the limits of my electricity consumptions. He charged me with 400 euros extra because as he says i consumed way beyond what i already pay with fixed tax in my contract. The problem is that i’m living alone, i have a full time job and i spend basically 4 hours a day at home not considering the 6-7 hours of sleep i get where everything is shutted down , during my free days im barely home since im spending time with my GF.
I don’t own a TV since a year, and i turn on one single light because i like a soft enlightened apartment. I never turn on the heaters (im scared of the consumptions) i dont use a microwave or a dishwasher.
I’ve been asking my GF that is german and she says that for me would be barely impossible to consume that amount of electricity since she saw the way I’m saving electricity, I’ve also asked my manager at work and even for her looks unrealistic.
Im having so much thoughts about the possibility of getting scammed with bills because i had problems with my previous land lord where i had to hire a lawyer to find out that he was scamming me, and after all the money i spent for that i really would not like to repeat the experience, is frustrating… How does this looks like? Those picture got sent me thought whatsapp from him.
Some picture are “edited” from him, basically he wrote over the picture with an orange color.
The blue was used by me to erase some personal informations…
Do you guys have any suggestion or opinion about that?

by Wir3d_