Msme act - medium scale co v/s small scale company

We are a small scale engineering company and have dispute about the goods and services render by a vendor, who is a medium scale company much larger than us. The vendor has invoked the provisions of Section 18 of MSME Act for recovery of the payment of disputed invoices. Is a medium scale company entitled to seek releif under MSME act against a small scale company? Is there any case law on this issue?