how big is that rootball? looks like a lot of soil vs plant

I suggest you repot it. Check the root health while you are doing this. Keep a close eye on it, but don't baby it or the opposite either.

i only received it 1 week ago and paid good money :( help

I didn't see the second and third shots earlier. With plants in general bottommost leaves only turning is taken to indicate a specimen is being kept too damp or too dry. Of course, oldest leaves will also color and drop periodically as a part of a natural progression. Otherwise premature dropping of leaves can indicate a nitrogen deficiency. Finally posts about problems with tropical house plants of some size bought at warehouse stores and brought home to ordinary room interiors I think are pretty much always based on these specimens having been trucked directly from greenhouse or even warm climate outdoor production operations to retailers. So that they are not acclimated to typical human living spaces at time of purchase. With in addition I suspect a percentage of the kinds presented actually never being suitable for use as house plants rather than greenhouse or outdoor garden features.