Service tax on gta

Dear Professional Collegues,

Please let me know weather a Goods Transport Agency has to add service tax on 100 % taxable amount in Consignment Note (Lorry Receipt) @ 12.36% or on 25%  of taxable amount, if its taking abatement under notification no 26/2012-ST dated 20/6/12 & weather it has to mention in Lorry Receipt abount abatement if it charges service tax on such abated amount.

Thanks in advance.