does amendment and petition extension will have same receipt number ?


My employer applied for my H1B amendment about 6.5 months back under normal mode which is still in progress. Now they have applied for my petition extension as my old petition is going to expire soon again in normal mode.

My question is will my new petition extension case be applied on top of my already existing H1 amendment case ? If so, will it have same receipt number ? will it take less time for me to get my extended petition since already 6.5 months has been passed. Or, will it again take 8-9 months more ?