If that's the case can anyone recommend top quality plastic strings for it!

Its this weird plastic

This cheap plastic toy is a great gift for a 5 year old, but besides that its not good for anything else.

are cheap plastic strings

The cheap plastic strings that come with it must be changed, though

However, I would recommend just tossing the cheap plastic case and invest in some new strings.

I can't stand those cheap plastic ukulele they sell to tourists in Hawaii.

Overall I like it and would recommend, as long as you don't pay more than $35, and don't mind some QC issues.