Every decision of ordinary or summary process can be challenged in higher courts.
Grounds can not be specified without knowing the material facts of your case, so locate a good lawyer and only a good lawyer,because a bad lawyer can lose a good case and a good lawyer can win a case which is seemingly lost.
Even if you get a good lawyer,study your case yourself as much as possible,be student of your case,a lawyer has a lot of cases,but you would be having a single one,so you can do a lot in winning your case.
Also offer a good money to your lawyer on winning point,but on winning only,which would be separate from his regular fees.
Wish you best of luck,if innocent.