Need some adulting opinions*

Lexi

So my bf has lived in the house we currently reside for 6 years. I moved in 4 months ago, but 6 months ago the sewage was backing up the toilet and into the shower as well (truly repulsive). It finally stopped and has been fine since. It started happening again a week ago. The landlord was contacted and called a plumber. He is also a certified plumber and told us after 3 days of this shit that he did something to the pipes or tank or whatever and it solved the problem for now. The plumber showed up today and the landlord told us the plumber said its because I flushed a tampon down the toilet (the cotton, not the applicator) and is demanding we pay for the plumber's visit. The toilet was backing up before I started my period and I was unaware the cotton wasnt flushable?? We also live in New Orleans and after the flooding last week I blamed the sewage and water board completely. (Edit: they stated they purposely shut off some water lines throughout the town to keep some specific areas from flooding, causing midcity to flood SO much worse) I'm just pretty pissed now I'm forking over hundred for this issue that was occurring long before any tampons were involved in the situation to begin with. Am I dumb for being mad about it?? I just want to know some opinions or advice regarding the situation. Idk what to do...