Vallejo weathering effects

Can anybody give any input on shelf life of Vallejo effects for which I received after being stuck on ship for 5 months from Asia which I found them to be in a solid mass not liquid I was able to crush up and you pInt shaker with results.
I have twice reach out to manufacturer with no results finding the dates of manufacturing can anybody have knowledge of reading UPC numbers of date of manufacturerd how long will these product stay active and work as stated in purpose does anyone have any input on this matter the retailer in HK said he would credit but did not I will longer do business with a business that sends out old product and PP slighted with retailer sad in Virginia