IMO, they'll be okay w/o a top-- they've got what looks like 3 or so inches of space above the rim where the water isn't filled.
See if someone on here can take them (in the buy, sell section), and if not, I'd take them back and just explain that they are male plakats sold to you as females, and you can't house them. Any decent fish store would be embarrassed of their mistake and take them back and give you your money in return.
yeah il try and take them back on monday.. are ther egonna be ok in there til monday?
Also im more worried about my other 3 "females" now.
If they have small Ventral things does that mean there female? cause there rest have just normal size ones atm!!
Also any other way to find out myself?
No1 is a gorgeous colour and the other two look like crowntails. You are best to get another 2 females to spread any aggression so maybe try and swap the males back at the shop just dont go for anything that looks remotely male lol! As for the white spot it is not a sure fire way of sexing them as many males have them too! 
