Hopefully this is the right subreddit, if not I apologize.

I moved into an apartment complex in December with someone that was already living there. It's been a messy situation ever since. Originally I was told I would be added to the lease but then couldn't because there was no one of the original lease still living in this unit. Therefore I would have to start a new lease. That's fine, works for me. Well, as soon as they submitted the new lease, they threw paperwork at us stating we owed over $300 in unpaid electricity bills from the last tenants. The apartment complex paid it when they received the bill in late December. Now the landlords say we owe them. This bill is for stuff from before I lived there. Even though it's a new lease and the bills are under a previous tenant's name, I'm told I still have to pay it because it's whoever lives in the unit that has to pay the unpaid amounts. Is this true? I am facing eviction threats and I don't know how I will be able to come up with this money. If anything, shouldn't they be going after the previous tenant? Any help or advice would be much appreciated, thank you.