Dollar Tree

Hi I am a employee for dollar tree. I had a situation with a customer last week and a coworker went and told the manager "I think he said something racist against that lady", well she assumed I was racist because of the situation for some reason idk why, she asked where something was and I told her and she got nasty and attitude so I tossed a small thing of fake eyelashes in the return cart 2 feet behind me so I can go help her and she took it as me getting attitude and said "oh f you I dont need your attitude you must be racist", well needless to say racist I am not and my manager had suspended me from work until a investigation is done. I'm not sure what investigation can be done against hearsay from another employee. I have tried to contact my manager several times and everyone refuses to answer me. She also suspended me without even asking me what happened which I think is wrong. I have tried getting my managers bosses number and she refused to give it to me. The other complaint I have is I feel like she is singling me out because there has been cases where customers have made complaints about other employees and managers at my store and they had no disciplinary action against them. One complaint was for a manager using dirty language and swearing outloud in front of customers and there kids, no disciplinary action against her has ever been takin. There is another cashier at work that makes rude comments that are basically sexual harassment and all the managers just laugh it off and say "oh hes a harmless old man." There is numerous other things that happen at my work that are being hush hush about because it's against work policy. Especially being in a romantic relationship between 2 managers of the same store. My problem is all this is going on and nobody else gets any kind of disciplinary action against them, but a coworker assumes he hears me say something that wasn't said and they immediately suspended me