Here is the Papamochani Ekadashi Vrat Katha..
There is a garden named Chaitrarath in Swarglok, where almost all Devtas go for relaxation and the rishis perform penance to please the Almighty. One day, Kamdeva wanted to take revenge on Rishi Medhavi and decided to disturb his penance. He sent Manjughosha, a dancer to distract the Rishi and break his concentration. Rishi Medhavi was enchanted by the dancer and began spending most of his time with her.
After a while the dancer became bored and asked the Rishi to let her go. She said that her parents would be waiting for her. The Rishi asked her to wait until night. Manjughosha then asked the Rishi if he was aware how many days and nights she had spend with him. When he began counting, the Rishi was furious when he realized that 75 years had passed and he had been duped by the dancer at the instigation of the Devtas. In his anger, he cursed the dancer.
Manjughosha pleaded with Medhavi for forgiveness. The Rishi took pity on her and said “O Devi, fast on Papmochani Ekadashi which arrives in the month of Fagan, for the full day and you shall be free.”
Medhavi Rishi then went to his father Rishi Chavan and told him the whole incident. He begged forgiveness and asked how he could be freed from the consequences of his sins. Rishi Chavan told him to keep a full fast on Papmochani Ekadashi in the month of Phagun. The Rishi Medhavi and the dancer both kept the fast and were freed.