Service tax

I have a query.I have procured an order for a compressor engine for a big Co. based in India.I have raised invoice including Service Tax @ 12.36% to Co. as my commission for this order. Co. besides manufacturing these compressors, also charges buyer for installation & maintenance of these compressors. Now,can the Co. avail rebate for Service Tax I have charged in my invoice.I am sure they are paying excise duty also.Can they offset the Service Tax amount which I paid, from Service Tax payable by them for other services they are offering to buyers. Kindly help. Thanks.