Is this bannable? Genuine question. (Scenario)

Ok, so you're currently losing a game hard, and now they have you cornered at the fountain. The majority of the enemy team is fed and have champions that would either CC you into the ground or destroy you where you stood, your minions are all pushed out against them but they don't bother pushing back and let their minions do the work (minions get stronger the more enemy towers are destroyed plus the inhibitor destroyed bonus). They just sit there spamming taunts and laughs and mastery emotes at your fountain preventing you from doing anything but sit there and continuously get BMd or killed. (It's even worst if they have a where the latter is more likely).

So, is this a bannable offence right there? Because I have encountered multiple cases of spawncamping from the whole enemy team where they keep getting off scott-fucking-free despite reports.

EDIT: Oh yes and how could I forget, they pull the 'gg ez pz' card at the end when they finally decide to win.