Laptop doesn't contain same amount of RAM as originally advertised

[CalvinP1]

I purchased the HP Pavilion 15-eco0751ms gaming laptop just yesterday and advertised as having 16 GB RAM I needed a laptop with 16GB. On the box it is packaged in it lists all the product details the same as listed in the original advertising which matches including the 16GB RAM.

The box contains a second list which reads 8GB SODIMM DDR4 SDRAM (I dont know what this all means) I'm assuming the laptop contains either 8GB RAM because of this or either 16GB because of the other list. This is all sending mixed messages  I can't talk to the store I bought it from they are closed today I can't log onto the laptop to veiw how much RAM is included if I wanted to exchange my wrongly provided product from the store it has to remain in a unused condition.

Can someone here explain to me if the wrong product has been given to me or not (I wanted 16GB RAM) I can't understand all the acronym around the list on my box that says 8GB. 

Thank you for reading this and thank you for your assistance. 

[banhien]

@CalvinP1 

I can't find HP Pavilion 15-eco0751ms , only HP Pavilion - 15-ec0751ms,. Its specs

     https://support.hp.com/us-en/document/c06459239

As shown: It ONLY has   8 GB DDR4-2400 SDRAM (1 x 8 GB). Where did you get it advertised  ? Please come to that store and ask.

Regards.