Approach the income tax department and file an application for rectification of challan if they accept. You may need to pay some out of pocket expenses (hope you understand what I want to say). Generally, they will do it, if you have filled a wrong section for TDS but I guess that this is not the case.
You may file a revised ITR and claim a refund as a last resort.
If you filled the wrong assessment year, then the only way I think is to file a revised ITR for that PAN.