Amanda Bynes is being sued by the rehab clinic she was admitted to ...

Amanda Bynes is being sued by her rehab clinic for not paying her bill.

The Easy A actress checked into the Creative Care Treatment Center earlier this year and the facility have claimed they haven't been paid the $2,467 she owes for the inpatient care she received on February 21 and 22.

According to documents obtained by The Blast, the facility wrote: "Amanda Bynes, was a client at our dual diagnosis residential treatment centre. She was at our facility for two days receiving inpatient treatment.

"Our monthly residential treatment rate is 37,000, divided by 30 days is $1,233.33 per day."

According to the company's website, their dual diagnosis treatment begins with a clinical assessment, followed by sessions with the "resident psychiatrist, registered nurses, our clinical director, therapists, and any other conciliatory staff members."

Amanda - who is under the conservatorship of her mother, Lynne, until 2020 - checked into the clinic after relapsing in her battle against drug addiction and other mental health issues.

Since leaving the facility, the 33-year-old star has been working hard on her planned fashion line, which she decided to launch after graduating from the Fashion Institute of Design & Merchandising.

Tamar Arminak, a lawyer for the actress and her family, recently reassured fans the She's The Man star was doing "remarkably well" after choosing for herself to re-enter treatment.

Tamar said: "I can tell you she's doing remarkably well, under the circumstances.

"This time around, she realised herself, after the Paper Magazine interview spread, that she really wasn't feeling like herself, all of the sudden.

"She wanted to address it right away before going back into show business and exploring showbusiness again.

"It was her decision and her choice to address the situation, seek treatment, which, I think, is an incredibly mature way to handle this type of thing.

"I think we're proud of her, her parents, I can certainly say are proud of her. Her family, they're on amazing terms, great terms, and looking forward to her success."

- Bang! Showbiz