Commission denied by broking house

I have a query : I worked with a broking house for insurance. We gave business of certain policies in 2010. The authorised person at a local office committed that the broking house would give renewal commission,after 1 year passed, the renewals were paid by client, the firm denied that they don't pay renewal commissions. We had nothing in writing ,it was verbal, when the same person was present in that company (broking house), we had communicated with the company's regional manager who kept on arguing on mail about sharing 50 % of renewals with us as we are sub brokers. we have the same communication on mail. Meanwhile the local employee of that company switched his job, there was no contact of the same company, since last 2 years the renewal premiums are paid by clients the company is not paying us the renewal commission.

Pl advise.