Do you mean feedback while muting the strings, and while the amplifier is set to high volume? If all of these are true, I think this may be microphonic feedback. In other words, some slighy loose coil windings in a pickup is vibrating at high volumn and inducing a squealing signal.
Does this happen with only one pickup selected, or all of them?
If necessary the offending pickup can be taken out and dipped in wax to prevent this problem. Make sure you research this carefully first though as the wire is very fragile!
As for returning - only if Squier normally dip these pickups to prevent microphony. If they normally don't do this, then yours may not have been done properly. You might like to talk with the dealer and see if this is regarded as a fault. I saw this once (on a cheap guitar I used to have), it was only when using extremely high gain, so I just ignored it.