The LW player isn't very good & it's playback can really suffer if you're actively uploading/downloading while you're trying to play files

The best advice I can offer you is to just disable the LW player & use something else. You'll probably find it a lot easier! The LW player's playlist management isn't the best either - it's a lot less painful to stick with iTunes

You won't have any joy asking for a refund from LW - they make a point of not giving refunds because basic LW is free (most features, including the player, are the same as Pro): Frequently Asked Questions - LimeWire

Providing you bought your Pro from the official site (payment to LimeWireLLC) Lime Wire » Download LimeWire & your Pro benefits are still current, Pro support is here: Lime Wire » LimeWire PRO Support Center